Chemical reactions are more likely to happen when

electrons are in an excited state
electrons are in the lowest possible energy level
electrons are part of a full octet
electrons are in the ground state

I think the correct answer from the choices listed above is the first option. Chemical reactions are more likely to happen when electrons are in an excited state. An excited-state atom is an atom in which the total energy of the electrons can be lowered by transferring one or more electrons to different orbitals.

Thermohaline circulation and gyres