Correct answer is (a) True
Easy explanation: Mercury has both advantages and disadvantages for use as the heat removing fluid. Its boiling point of 357°C at atmospheric pressure may be easily raised to 400-450°C by the application of nitrogen pressure. It is fluid at room temperature and introduces no hazard of equipment damage due to solidification through accidental cooling because of shutdown of equipment. Mercury vapour is toxic; the liquid is heavy; and leaks in the pressure system are difficult to prevent.