Answer:
B)
Step-by-step explanation:
The prime factors of 15 are: 1,3,5,15
The prime factors of 21 are: 1,3,7,21
The prime factors of 38 are: 1,3,13,39
The prime factor of 42 is : 1,2,3,6,7,14,21,42
IDK i just really hate it how you get only a limit of answers for free for one day.
I believe the correct answer is B.