Answer:
B
Step-by-step explanation:
A) The sea of electrons only happen with metalic bond, a bond with two metalic elements.
B) As both elements in ammonia (N and H) are non-metals we don't observe an transfer of electrons, both elements share the number of electrons needed to stablize it (3 electrons for the N and 1 for the H).
C) To have a transfer of electrons, we need a bond between a metal and a non-metal, in this case, N and H are non-metals, so this doesn't happen.
D) The electrons are shared, only the electrons nothing happens between the orbitals.