Question

spark plugs are identified by three different features: thread size or diameter, reach or length of the thread, and heat range or

a. plated metal shell
b. internal resistor
c. operating temperature
d. center electrode

Explanation:

Spark plugs' heat range is related to their operating temperature. A spark plug's heat range indicates how well it can transfer heat away from the combustion chamber. A "cold" spark plug transfers heat quickly (suitable for high - performance, high - temperature engines), while a "hot" spark plug transfers heat more slowly (better for low - performance, lower - temperature engines). The other options (plated metal shell, internal resistor, center electrode) are components of a spark plug but not directly related to the concept of heat range in the same way as operating temperature.

Answer:

C. Operating temperature