44. If $f$ is the solution of $x f ^ { \prime } ( x ) - f ( x ) = x$ such that $f ( - 1 ) = 1$, then $f \left( e ^ { - 1 } \right) =$ (A) $- 2 e ^ { - 1 }$ (B) 0 C) $e ^ { - 1 }$ (D) $- e ^ { - 1 }$ (E) $2 e ^ { - 2 }$
44. If $f$ is the solution of $x f ^ { \prime } ( x ) - f ( x ) = x$ such that $f ( - 1 ) = 1$, then $f \left( e ^ { - 1 } \right) =$\\
(A) $- 2 e ^ { - 1 }$\\
(B) 0\\
C) $e ^ { - 1 }$\\
(D) $- e ^ { - 1 }$\\
(E) $2 e ^ { - 2 }$\\