Consider the estimated relationship: $=50+50$X$.$

$1.$ The average level of Y$,$ if X $=0,$ is $50.$

$2.$ For each unit increase in $\backslash$alpha $,$ Y will increase by $50$ units.

$3.$ For each unit increase in X$,$ Y will increase by $50$ units.

Which of the following is correct?

A$)1$

B$)2$

C$)1$ and $2$

D$)1$ and $3$