Answer:
Tree A
Explanation:
Let me put this question a different way. Which tree will be the tallest at the end of the year?
Well, let's think about it. 12 months later, Tree A will have grown 4.15x12=49.8 inches. Tree B will have grown 4.2x12=50.4 inches. As 50.4 is greater than 49.8, we can see it is Tree B that was the tallest at the end of the year. So we can conclude that Tree B grows faster. This would mean that Tree A grew at a slower rate for the first year.
Hope this helps