The Recurrence Relation for the Differential Equation $x y ^ { \prime \prime } + 2 y ^ { \prime } - x y = 0$

Multiple Choice

The recurrence relation for the differential equation $x y ^ { \prime \prime } + 2 y ^ { \prime } - x y = 0$ is

A) $c _ { k } ( k + r ) ( k + r - 1 ) + c _ { k - 2 } = 0$
B) $c _ { k } ( k + r ) ( k + r - 1 ) - c _ { k - 2 } = 0$
C) $c _ { k } ( k + r + 1 ) ^ { 2 } - c _ { k - 2 } = 0$
D) $c _ { k } ( k + r + 2 ) ( k + r + 1 ) + c _ { k - 2 } = 0$
E) $c _ { k } ( k + r ) ( k + r + 1 ) - c _ { k - 2 } = 0$