问题如下：
What two activities of life insurance companies have opposite exposures to longevity risk?
选项：
A.Term life insurance and whole life insurance
Term life insurance and endowment life insurance
Whole life insurance and annuities
None of the above
解释：
C. Most forms of life insurance have mortality risk (i.e., the risk that policyholders will die earlier than expected). Annuities have longevity risk (i.e., the risk that policyholders will live longer than expected).
这道题问的是跟longevity风险相反的exposure是什么，longevity是怕人活的久了赔付风险高，那个whole life insurance 是希望人活的久，不希望过早死亡而进行赔付，这个敞口跟longevity是相反的，我可以理解，但是annuities have longevity risk 这不就是说明跟longevity有着相同的exposure吗？并不是相反的exposure呀？
