4d(2d-9)

A) 8d-36d

B) -d

C) -28d^2

D) 8d^2-36d

D) 8d^2-36d

To simplify the expression 4d(2d-9), we will distribute the 4d to both terms inside the parentheses.

First, distribute 4d to 2d:
4d * 2d = 8d^2

Then, distribute 4d to -9:
4d * -9 = -36d

Putting the terms together, the simplified expression is:
8d^2 - 36d

Therefore, the correct answer is D) 8d^2-36d.