Pick up the correct statement from the following:

• Air screw converts the energy given by the engine into speed
• The propellers which are driven by turbine engines, are technically called turboprops
• The aircrafts which obtain the thrust directly from turbine engine, are called turbo-jets
• The aircraft which is filled with a fan infront of turbo-jet engine, is called turbofan propelled aeroplane
• All the above.