A stock sells for $30 and a 6-month call on the stock with a $30 strike trades for $5. If the stock goes to $40, which of the following is true:

a. Spending $30 to buy 1 share of stock offers the greatest percentage return on investment

b. Spending $30 to buy 6 call options offers the greatest percentage return on investment

c. Buying the 1 share of stock for $30 has the same percentage return as buying 6 call options for $30

d. Writing 6 call optionsoffers a risk-free return