In the Previous Problem, a Second Solution Is
A) $y _ { 2 } = e ^ { x }$

Multiple Choice

In the previous problem, a second solution is

A) $y _ { 2 } = e ^ { x }$
B) $y _ { 2 } = x \int e ^ { x } / x ^ { 2 } d x$
C) $y = 1 + \sum _ { k - 1 } ^ { \infty } c _ { k } x ^ { k } , \text { where } c _ { k } = ( k - 1 ) / ( k ( k + 1 ) )$
D) $y = 1 + \sum _ { k = 1 } ^ { \infty } c _ { k } x ^ { k } , \text { where } c _ { k } = 1 / k ^ { 2 }$
E) none of the above