we know that
A relationship between two variables, x, and y, represent a direct variation if it can be expressed in the form [tex]y/x=k[/tex] or [tex]y=kx[/tex]
In this problem we have
[tex]p=20.8\\q=31.2[/tex]
Find the value of k
[tex]k=q/p[/tex]
Substitute the values
[tex]k=31.2/20.8[/tex]
[tex]k=1.5[/tex]
The linear equation is
[tex]q=1.5p[/tex]
For [tex]q=15.3[/tex]
Find the value of p
Substitute in the linear equation and solve for p
[tex]15.3=1.5p[/tex]
[tex]p=15.3/1.5=10.2[/tex]
therefore
the answer is the option a
[tex]10.2[/tex]