Answer
a is the input with years as the units.
H is the output with inches as the units.
This is not a function.
Work Step by Step
We know that a is the input because it is inside the parentheses. H is the output because it is the "coefficient" of the parentheses. The units of years and inches are both given in the problem. This is not a function because multiple kids could be the same age but have different heights.
