In the Slutsky Equation For $\partial x _ { i } / \partial p _ { j }$

In the Slutsky equation for $\partial x _ { i } / \partial p _ { j }$ ,the income effect is given by

A) $x _ { i } \partial x _ { i } / \partial I$ .
B) $x _ { j } \partial x _ { i } / \partial I$ .
C) $x _ { i } \partial x _ { j } / \partial I$ .
D) $x _ { j } \partial x _ { j } / \partial I$ .