$\text{All flies eats bats}$
$\forall x (F(x) \rightarrow \exists y (E(x,y) \wedge B(y)) ) \text{As it is not given that all flies eats all Bats}$
$\text{Every fly is eaten by some bat}$
$\forall x (F(x) \rightarrow \exists y (E(y,x) \wedge B(y)))$
$\text{bats eat only flies}$
$\forall x (B(x)\rightarrow \exists y (E(x,y) \wedge F(y)))$
$\text{every bat eats flies}$
$\forall x(B(x)\rightarrow \exists y(E(x,y) \wedge F(y)))$
@Arjun sir can you verify all , i am not sure about option$3$