It is basically a trick question. Firstly we have to ficus on the given formula to get to the answer for this question.
2l + 2w = 16
2(l + w) = 16
l + w = 8
l = 8 - w
Mow w cannot be less than 1. So the length of the rectangle cannot be more than 7. So we can conclude that 7 inches is the correct option or the first option is the correct option among the given options.
Hope this helped!!!!!