Riddle

Without coolant, you'll have some trouble with this.

Choose an answer

A.Engine
B.Battery
C.Thermostat
D.Radiator
Hint: It's a word with 8 letters, starting with "R".

Answer

Radiator

Why this is the answer

A car's radiator relies on coolant to prevent the engine from overheating.

This riddle is filed under Hard/Difficult Riddles and rated Medium.