In a hydrogen atom, a transition occurs because nature does not like to be in a higher energy state.

A spin-flip transition occurs rarely because nature does not like to be in a higher energy state. A spin-flip transition results in the atom going through a high energy transition, and as such, will not be desired to happen frequently as nature does not desire to be in such a high energy state often.

The answer is a.  i hope this

Answermake them get very hot and over time wear them out;