Answer
Option B is correct.
15 is the greatest common factor of 45 and 120.
Step-by-step explanation
The factors of a number are the numbers that can divide that number without leaving a remainder.
The factors of 45 include 1, 3, 5, 9, 15 and 45
The factors of 120 include 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60 nd 120.
We can see that the greatest factor that these two numbers have in common is 15.
Hope this Helps!!!