单选题 An investor buys a call option with a $25 exercise price priced at $4 and writes a call option with a $40 exercise price priced at $2.50. If the Price of the stock increases to $50 at expiration and the options are exercised on the expiration date, the net profit at expiration (ignoring transaction costs) is:

A. $8.50.
B. $13.50.
C. $16.50.

【正确答案】 B

【答案解析】The net cost is: $4 and received $2.50= $1.50. Gain or loss from the calls : long call $50 - $25 = gain of $25. Written call $50- $40= $10 loss. net position $25- $10= $15. Overall gain or loss: gain $15 -cost $1.50 = $13.50 gain.