Final answer:
Submarines currently do not use any of the mentioned torpedoes exclusively.
Step-by-step explanation:
The type of torpedoes currently used exclusively by submarines is None of the above. Nuclear torpedoes, electric torpedoes, and chemical torpedoes are not used exclusively by submarines. Submarines typically use a variety of torpedoes depending on their mission and requirements. These torpedoes can be powered by different propulsion systems and may carry different types of warheads.