Let $\mathbf { r } = x \mathbf { i } + y \mathbf { j } + z \mathbf { k }$

Multiple Choice

Let $\mathbf { r } = x \mathbf { i } + y \mathbf { j } + z \mathbf { k }$ and $r = | \mathbf { r } |$ .
Find $\nabla \cdot ( \mathbf { r } )$ .

A) 5
B) 3
C) 1
D) 2
E) None of these