设{u_n}是单调增加的有界数列，则下列级数中收敛的是(  )．

A 1 B 2 C 3 D 4

A 可导点，极值点 B 不可导点，极值点 C 可导点，非极值点 D 不可导点，非极值点

A <img width="51" height="49" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232624_2101.jpg" /> B <img width="61" height="49" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232626_1476.jpg" /> C <img width="62" height="43" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232626_4132.jpg" /> D <img width="51" height="44" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232628_3351.jpg" />

A <img width="122" height="38" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232628_6164.gif" /> B <img width="116" height="38" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232630_4757.gif" /> C <img width="108" height="38" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232630_8820.gif" /> D <img width="120" height="38" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232632_6164.gif" />

A r(A)=2，r(<img width="24" height="42" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232633_0382.gif" />)=3 B r(A)=2，r(<img width="24" height="42" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232633_0382.gif" />)=2 C r(A)=1，r(<img width="24" height="42" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232633_0382.gif" />)=2 D r(A)=1，r(<img width="24" height="42" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232633_0382.gif" />)=1

A P(A∪B)=P(A)+P(B) B P(AB)=P(A)P(B) C P(A<img width="24" height="42" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232635_4445.gif" />)=P(B<img width="24" height="42" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232633_0382.gif" />) D P(AB)=P(<img width="24" height="42" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232633_0382.gif" /><img width="24" height="42" src="https://www.beizhujiaoyu.com/uploads/202208/20210427232635_4445.gif" />)

A 与μ无关，而与σ²有关 B 与μ有关，而与σ²无关 C 与μ，σ²都有关 D 与μ，σ²都无关