State whether the following statements are true $(T)$ or false $(F)$.
$(a)$ An electric motor converts mechanical energy into electrical energy.
$(b)$ An electric generator works on the principle of electromagnetic induction.

• A
  $(a)-(T); (b)-(F)$
• B
  $(a)-(F); (b)-(F)$
• C
  $(a)-(F); (b)-(T)$
• D
  $(a)-(T); (b)-(T)$