As marta built a square fence around her garden, she wondered how much she would have to pay if she increased the length of each side of the fence by the same number of meters. each meter of fence cost 3 dollars. which of the following functions best describes the additional amount of money marta will have to spend, in dollars, if she increases each side of the fence by m meters? a. f(m) = 1.5m b. f(m) = 3m c. f(m) = 6m d. f(m) = 12m