The dimensional formula for magnetic flux is:

The correct option is A $\left(M{L}^2{T}^{-2}{A}^{-1}\right)$
The magnetic flux if given by

$\varphi =BAcos\theta$

If $cos\theta =1$

The maximum magnetic flux, $\varphi =BA$. . . . . .(1)

where, $B=$ magnetic field

$A=area$

The dimensional formula for magnetic field,

$F=qvB$

where, $v=$ velocity

$q=$ charge,

$B=$ magnetic field

$\left[B\right]=\frac{M^1{L}^1{T}^{-2}}{\left[A^1{T}^1\right]\left[L^1{T}^{-1}\right]}$

$\left[B\right]=\left[M^1{L}^0{T}^{-2}{A}^{-1}\right]$

for area, $\left[A\right]=\left[M^0{L}^2{T}^0\right]$

The dimensional formula for magnetic flux,

$\left[\varphi \right]=\left[M^1{L}^0{T}^{-2}{A}^{-1}\right].\left[M^0{L}^2{T}^0\right]$

$\left[\varphi \right]=\left[M^1{L}^2{T}^{-2}{A}^{-1}\right]$

The correct option is A.