Option D is the correct answer because “hypochondriac “ means a person who is abnormally anxious about their health, hence it coincides with the statement given.
Option A is incorrect because “maverick” means an unorthodox or independent-minded person, which downstairs necessarily mean he believes he is always ill, hence it is incorrect.
Option B is incorrect because “metaphysics” means the branch of philosophy that deals with first principle of things, hence it is incorrect.
Option C is incorrect because “neophyte” means a person who is new to any subject or thing in general.