$\text { Find the particular solution of the differential equation } \frac { d r } { d s } = e ^ { y - 7 s } \text { that satisfies the }$

Multiple Choice

$\text { Find the particular solution of the differential equation } \frac { d r } { d s } = e ^ { y - 7 s } \text { that satisfies the }$ initial condition $r ( 0 ) = 0$ .

A) $r = \ln \left( 7 + e ^ { - 7 s } \right) + C$
B) $r = \ln ( 7 ) - \ln \left( 6 + e ^ { - 7 s } \right)$
C) $r = e ^ { \gamma - 7 s }$
D) $r = \ln \left( \frac { 8 + e ^ { - 7 s } } { 7 } \right)$
E) $r = \left( 1 + e ^ { - 7 s } \right) ^ { 7 }$