请问在option 中的long position， potential risk是option premium，为什么是current market value of option而不是过去买这个option时的premium？具体题目为经典题通关课3.5
1. A call option the bank purchased for 30$,the current market price of the option is $35.
问题：
the current potential credit loss of the bank's call option position is closest to ()
答案：35$
