Which sequence could be partially defined by the recursive formula f (n + 1) = f(n) + 2.5 for n ≥ 1?

a. 2.5, 6.25, 15.625, 39.0625, …

b. 2.5, 5, 10, 20

c. –10, –7.5, –5, –2.5, …

d. –10, –25, 62.5, 156.25