A small tree was planted at a height of 5 feet. The tree has been planted for 16 months, and is now 61 feet tall. Which equation could
be used to find x, the average number of feet the tree grew each month?
A. 5x + 16 = 61

B.16x + 5 = 61
C. 61x + 5 = 16
D. 16x + 61 = 5