Hydrogen fuel cell vehicles produce one of the following as "exhaust"

1. Hydrogen fuel cell vehicles (FCEVs) use a fuel cell to convert the chemical energy of hydrogen into electricity, which then powers an electric motor. 2. The fuel cell combines hydrogen (H2) from the tank with oxygen (O2) from the air. 3. The basic chemical reaction occurring in the most common type of fuel cell (Proton Exchange Membrane or PEM fuel cell) is: 2H₂ + O₂ → 2H₂O + Energy (electricity and heat). 4. The only byproduct or "exhaust" emitted from the vehicle's tailpipe is water (H₂O), usually in the form of vapor. 5. Options (A) NH3 (Ammonia), (B) CH4 (Methane), and (D) H2O2 (Hydrogen Peroxide) are not the primary exhaust products of a typical hydrogen fuel cell vehicle. 6. Therefore, the correct answer is (C) H₂O.