Which of the letters represent an alkaline earth metal?

The alkaline earth metals are found in Group 2 of the Periodic Table, and they include the elements beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). Therefore, any letter representing these elements would indicate an alkaline earth metal. For example, if the letters in question are Be, Mg, or Ca, then they represent alkaline earth metals.