Final answer:
In the function f(t) = 220(1.015)^t, 'a' represents the initial value or starting value of the function.
Step-by-step explanation:
In the function f(t) = 220(1.015)^t, the 'a' represents the initial value or starting value of the function. It is the value of the function when t = 0. In this case, 'a' is equal to 220, so the correct answer is a) 220.