Actual Sales of autos at Fred's Mercury for the months of January, February are $15$ and $20$ respectively. However, the sales forecasts for these months were $10$ and $25$ respectively. Hence, the Mean Squared Error $($MSE$)$ of this $2$ month forecast is:

$-5$ for January and $5$ for February.

$0$

$5$

None of the above.

$25$