Which type of motor will work as single excited motor? 

The correct answer is option 2):(Three phase squirrel cage motor )

Concept:

• A three-phase synchronous motor is a doubly excited machine, whereas an induction motor is a single excited machine.
• A singly-excited system is type of excitation system used in electromechanical energy conversion which requires only one coil to produce the magnetic field. In the singly-excited system, there is only one set of electrical input terminals and one set of mechanical output terminals

Additional InformationSquirrel cage rotor:

• It consists of a laminated cylindrical core having parallel slots on its outer periphery.
• One copper or aluminum bar is placed in each slot. All these bars are joined at each end by metal rings called end rings.
• This forms a permanently short-circuited winding which is skewed by some angle.
  
• The rotor is not connected electrically to the supply but has current induced in it by transformer action from the stator.
• Most of the 3-phase induction motors use squirrel cage rotors because of their simple and robust construction enabling them to operate in the most adverse circumstances.
• It suffers from the disadvantage of a low starting torque. It is because the rotor bars are permanently short-circuited and it is not possible to add any external resistance to the rotor circuit to have a large starting torque.