A sequence has its first term equal to 4, and each term of the sequence is obtained by adding 2 to the previous term. If f(n) represents the nth term of the sequence, which of the following recursive functions best defines this sequence? (1 point)

a
f(1) = 2 and f(n) = f(n − 1) + 4; n > 1

b
f(1) = 4 and f(n) = f(n − 1) + 2n; n > 1

c
f(1) = 2 and f(n) = f(n − 1) + 4n; n > 1

d
f(1) = 4 and f(n) = f(n − 1) + 2; n > 1