Step 1: Understand Money Bills.
A Money Bill deals only with taxes, government borrowing and public funds, and follows a special procedure.
Step 2: Find the deciding authority.
Article 110(3) says if any question arises whether a bill is a Money Bill, the Speaker of the Lok Sabha decides, and that decision is final.
Step 3: See why the Speaker.
Money Bills start only in the Lok Sabha, so the Speaker certifies them.
Step 4: Rule out the others.
The Finance Minister only introduces the bill, the President only gives assent, and the Prime Minister has no such power.
Answer: Speaker of the Lok Sabha (Option 3).