A speculator buys a call option for $3, with an exercise price of $50. The stock is currently priced at $49, and rises to $55 on the expiration date. The speculator will exercise the option on the expiration date (if it is feasible to do so). What is the speculator's profit per unit?
a. $1
b. $5
c. $2
d. −$1
e. −$2