Materials that do not allow electric current to pass through them are called _______.

insulators 

The correct answer is option 2. insulators.

Materials that do not allow electric current to pass through them are called "insulators."

When electricity passes through insulators, it encounters a significant amount of resistance, and as a result, very little or no current can pass through.

Common examples of insulators include:

• Rubber
• Glass
• Plastic
• Porcelain
• Wood
• Air (under certain conditions)