You win a prize and are offered two choices. Which of the choices could be represented by a linear equation?

Choice A: $100 on January 1, $200 on February 1, $400 on March 1, $800 on April 1, and so on, with the amount doubling each month.

Choice B: $50 the first month, $100 the second month, $150 the third month, and so on, with $50 added each month.