Concept:Differentiate an exponential function with base other than e using the chain rule: dxdau=au⋅lna⋅dxdu.Explanation:Given y=32x2+7x+1.Let u=2x2+7x+1. Then dxdu=4x+7.Differentiating: dxdy=3u⋅ln3⋅dxdu.Substitute back: dxdy=32x2+7x+1⋅ln3⋅(4x+7).Note: ln3=loge3.Answer:32x2+7x+1⋅loge3⋅(4x+7), which matches option B.