From p(c)=0, we know? xp(x) = 0
At this time? Xp(x) → q(a) is true.
When x=b, q(x)=q(b)= 1.
Obviously at this time? Xp(x) → q(b) is true.
When x=c, q(x)=q(c)=0
From p(c)=0, we know? xp(x) = 0
At this time? Xp(x) → q(c) is true.
To sum up, the proposition is always true.