Answer:
D!!!
Step-by-step explanation:
<h2>
The top of the ladder is descending at 0.3 m/s.</h2>
Step-by-step explanation:
By Pythagoras theorem we know that
Hypotenuse² = Base² + Perpendicular²
h² = b² + p²
We have for ladder
h = 5 m
b = 3 m
5² = 3² + p²
p = 4 m

Differentiating h² = b² + p² with respect to time

The top of the ladder is descending at 0.3 m/s.
(-4)^-3 =
-4^-3 = 
Basically in this situation there is no difference whether parenthesis are used or not.