[CFA一级]interest rate变化和option的关系 afternoon, interest, increase, morning, option

agulani

2011 mock afternoon:95题。为什么interest rate rise,call option value increase? 而2011 morning:101题，下面的解释是when interest rate fall,the price of the embedded call option increase? 应该怎么理解这两题？interest rate和option的关系怎么看？