This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to test spark plug wires
Check for symptoms.
Defective spark plug wire leave tell-tale signs of their deterioration, including :
An erratic idle engine misfire radio interference decreased fuel mileage failed emissions tests due to elevated hydrocarbon emissions or a fault code indicating cylinder misfire. Check engine light
Inspect the wires.

Choices:
[a]. Remove two bolts closest to the battery compartment and lift the battery cover by hand. Separate the wires by pulling the cover back to the positive (+) and negative (-) terminals.
[b]. Use a flashlight or an area with good lighting to perform a visual inspection of the spark plug wires. Look for physical damage to the wires or boots such as cuts and scorch marks.
[c]. Before attempting to test spark plug wires on a grounded engine, check the plastic casing underneath the coil. The casing or coil will have a designation indicating its discoloration and length, so see a diagram to help with choosing the right wire for you.
[d]. Check the wires for broken terminals (most of the time it is no indication of the source of the engine misfire), smaller holes or where fuel leaks. Confirm the holes by lighting the spark plug wires with a match.
The answer is:
[b].