Which two statements are equivalent:

elephant child $(y,x)$fly$(y)$

fly $(y)$

elephant $(x)((notEEy(ld(y,x{)}^{{?}^{?}}$notlly$(y)))$happ$(x))$

elephant fly $(y)$ happy $(x)$

Select one:

a$.1,3$

b$.2,4$

c$.$ None

d$.1,4$

e$.2,3$