根据下面资料，回答31-35题
American farmers have been complaining of labor shortages for several years now. Given a multiyear decline in illegal immigration, and a similarly sustained pickup in the U.S. job market, the complaints are unlikely to stop without an overhaul of immigration rules for farm workers.
Congress has obstructed efforts to create a more straightforward visa for agricultural workers that would let foreign workers stay longer in the U.S. and change jobs within the industry. If this doesn't change, American businesses, communities, and consumers will be the losers.
Perhaps half of U.S. farm laborers are undocumented immigrants. As fewer such workers enter the country, the characteristics of the agricultural workforce are changing. Today's farm laborers, while still predominantly born in Mexico, are more likely to be settled rather than migrating and more likely to be married than single. They're also aging. At the start of this century, about one-third of crop workers were over the age of 35. Now more than half are. And picking crops is hard on older bodies. One oft-debated cure for this labor shortage remains as implausible as it's been all along: Native U.S. workers won't be returning to the farm.
Mechanization is not the answer, either--not yet, at least. Production of corn, cotton, rice, soybeans, and wheat has been largely mechanized, but many high-value, labor-intensive crops, such as strawberries, need labor. Even dairy farms, where robots do a small share of milking, have a long way to go before they're automated.
As a result, farms have grown increasingly reliant on temporary guest workers using the H-2A visa to fill the gaps in the workforce. Starting around 2012, requests for the visas rose sharply; from 2011 to 2016, the number of visas issued more than doubled.
The H-2A visa has no numerical cap, unlike the H-2B visa for nonagricultural work, which is limited to 66,000 a year. Even so, employers complain they aren't given all the workers they need. The process is cumbersome, expensive, and unreliable. One survey found that bureaucratic delays led the average H-2A worker to arrive on the job 22 days late. The shortage is compounded by federal immigration raids, which remove some workers and drive others underground.
Petitioning each year for laborers————and hoping the government provides enough, and that they arrive on time——is no way to run a business. In a 2012 survey by the California Farm Bureau,71 percent of tree-fruit growers and nearly 80 percent of raisin and berry growers said they were short of labor. Some western growers have responded by moving operations to Mexico. Without reliable access to a reliable workforce, more growers will be tempted to move south.
According to a report by the Partnership for a New American Economy, Americans are consuming more fresh produce, which is good. But a rising share of it is grown elsewhere. From 1998 to 2000,14.5 percent of the fruit Americans consumed was imported. Little more than a decade later, the share of imported fruit had increased to 25.8 percent.
In effect, the U.S. can import food or it can import the workers who pick it.
What problem should be addressed according to the first two paragraphs?

A Discrimination against foreign workers in the U.S.

B Biased laws in favor of some American businesses.

C Flaws in the U.S. immigration rules for farm workers.

D Decline of job opportunities in U.S. agriculture.