A speculator believes that the price of a certain stock will rise. The current stock price is $39, and a three-month call with a strike of $40 costs $3.90. The speculator has $7,800 to invest. Consider two alternative strategies, one involving an investment in the stock and the other involving investment in the option. What are the potential gains or losses of the two strategies under the following scenarios: (a) stock price is $50 and (b) stock price is $25?