Q$1.$ Construct a formal proof of validity for the following argument:

$"$ If either Anand enrolls or Baskar enrolls, then Chander does not enroll. Either Chander enrolls or Baskar enrolls.If either Baskar enrolls or Anand does not enroll then Dhanush enrolls. Anand enrolls. Therefore either Dhanush enrolls or Baskar does not enroll."

Use the following notations:

$A$ : Anand enrolls. $B$: Baskar enrolls. $C$ : Chander enrolls. $D$ : Dhanush enrolls. $\%$