22. Option values (S21-3) How does the price of a call option respond to the following changes, other things equal? Does the call price go up or down?

a. Stock price increases.

b. Exercise price is increased.

634 Part Seven Options

c. Risk-free rate increases.

d. Expiration date of the option is extended.

e. Volatility of the stock price falls.

f. Time passes, so the option’s expiration date comes closer.