Which of the following machinery transforms electrical energy into mechanical energy?

An electric motor is a device that transforms electrical energy into mechanical energy. 

A dynamo is an apparatus that transforms mechanical energy into electrical energy. 

A transformer is used to convert high voltage to low voltage and low voltage to high voltage (or low current).

Inductors are wire coils that are twisted around hollow tubes or any ferromagnetic material with an iron core to boost their inductive value. 

Therefore, the electric motor is the right answer.