Answer – B (Electrons)
When atoms combine, their nucleons fuse to produce a new nucleus and interactions occur between their electrons, particularly the outer valence electrons. The interaction between the outer valence electrons of the combining atoms forms bonds between them.
I believe the answer is head-on and port (left). The side lights are usually visible to vessels approaching from the front or the side. The red light usually indicates a vessel's port (left) side while the green light indicates a vessel's starboard (right) side. These lights ensure that there is safety at night as the vessels navigate.
