Why Is the Nuclear Binding Energy for ⁴He Greater Than

Why is the nuclear binding energy for ⁴He greater than that for ³¹P?

A) Because the nulceons of He are more closely packed than any other element.
B) Because helium has an even number of both protons and neutrons.
C) Because helium is one of the noble gases, with a full electron shell and thus a stable nuclear number.
D) Because ³¹P is one of the few unstable isotopes of one of the smaller elements.
E) It is not; the nuclear binding energy becomes greater for heavier elements.