4-A 100-amp circuit breaker feeds a raceway that's separated by a nonmetallic box about halfway down its length. Which of the following sizes of copper equipment grounding conductor should be...

4-A 100-amp circuit breaker feeds a raceway that's separated by a nonmetallic box about halfway down its
length. Which of the following sizes of copper equipment grounding conductor should be installed in this
feeder circuit?
A. No. 2
B. No. 6
C. No. 4
D. No. 8