A1:
Assume B=true
A= {false, true, false}
So, LHS = false and RHS=true
So, invalid.
A2:
Lets consider there 2 variables in domain viz. x1 and x2
So, LHS
= (A(x1) + A(x2)) $\rightarrow$ B
= (A(x1) + A(x2))' + B
= (A'(x1) . A'(x2)) + B
= (A'(x1) + B) . (A'(x2) + B)
= (A(x1)$\rightarrow$ B) . (A(x2)$\rightarrow$ B)
= Vx (A(x) $\rightarrow$ B)
= RHS
So, this is suficient to get to options.