4. A call option to buy 10,000 at a strike price of $1.80 = 1.00 is equivalent to

a. A put option on 10,000 at a strike price of $1.80 = 1.00.

b. A call option on $18,000 at a strike price of $1.80 = 1.00

c. A put option on $18,000 at a strike price of $1.80 = 1.00.

d. None of the above