Petroleum jelly is applied to the electrical connections to the lead-acid battery

prevent local heating
prevent short-circuiting
reduce path resistance
prevent corrosion

The correct answer is: D. prevent corrosion.

Petroleum jelly is a type of grease that is made from petroleum. It is a thick, sticky substance that is often used to protect metal surfaces from corrosion. When petroleum jelly is applied to the electrical connections to a lead-acid battery, it forms a barrier between the metal and the air, which helps to prevent the metal from rusting.

The other options are incorrect because:

  • Petroleum jelly does not prevent local heating. In fact, it can actually trap heat and make the problem worse.
  • Petroleum jelly does not prevent short-circuiting. Short-circuiting is caused by a direct connection between two electrical terminals, and petroleum jelly will not prevent this from happening.
  • Petroleum jelly can reduce path resistance, but this is not its primary purpose. The main purpose of petroleum jelly is to prevent corrosion.