Solving for Which Variable in Which Equation Involves the Least $7 x=42$

Multiple Choice

Solving for which variable in which equation involves the least amount of work?
$7 x=42$
$x-8 y=78$

A) $\mathrm{x}$ in equation 1
B) y in equation 1
C) $x$ in equation 2
D) y in equation 2