Select the best answer to make the statement true, and place the letter of your answer in the space provided.
The cable used in the low-voltage part of remote control systems __________
a. is the same as cable used in standard 120 -volt systems.
b. requires special insulation.
c. must allow fuses or circuit breakers to be easily installed.
d. is low in cost compared to cable used in standard 120-volt systems.