Miriam has a bamboo plant that is 20 centimeters tall. the plant grows at a rate of 2 centimeters a week. which recursive formula gives the plant’s height at any week in the future?

I've read this question before, it had choices:
a.next=20*now+12,starting at 12
b.next=now+2,starting at 20
c.next=now+20,starting at 2
d.next=now+20,starting at 12
e.next=12*now+20,starting at 20

20 cm is the constant. It's the initial height. 2cm per week is increase in growth per week.

h = 20 + 2x   where x is the number of weeks.

The recursive formula would be: c.next=now+20,starting at 2 

The answer would be a