Consider the following PROLOG program:

teaches$($john$,$ math$).$

student$($bob$).$

student$($ali$).$

takes$($bob$,$ science$).$

takes$($ali$,$ math$).$

knows$($X$,$ Z$)$ :$-$ student$($X$),$ takes$($X$,$ Y$),$ teaches$($Z$,$ Y$).$

Which one is correct about the query $"?-$ knows$($X$,$john$)"?$

A$.$ It is entailed from the program with X$=$bob.

B$.$ It is entailed from the program with X$=$ali.

C$.$ It is entailed from the program with X$=$math.

D$.$ It is not entailed from the program.