c
(c)
When elevator goes up with some acceleration upward, due to pseudo force acting downwards. Value of $g$ increases to $g^{\prime}$.
If $g$ increases to $g^{\prime}$,
$\text { i.e., } g^{\prime}=g+a$
$\because P=\rho g h=\rho(9+a) h h^{\prime}=$ constant
Then, $h^{\prime} < h$
i.e., $h^{\prime} <76 \,cm$