The derivatives of (2x + 1)(3x + 1) is

A.
12x + 1 
B.
6x + 5 
C.
6x + 1 
D.
12x + 5
Correct Answer: Option D
Explanation
2x + 1 (frac{d(3x + 1)}{mathrm d x}) + (3x + 1) (frac{d(2x + 1)}{mathrm d x})
2x + 1 (3) + (3x + 1) (2)
6x + 3 + 6x + 2 = 12x + 5