We need to find The greatest common factor (GCF) of 6930 and 288

Lets solve it using two methods

Method 1: Prime Factorization

6930 = 7* 9 * 10 * 11 = \(2^1 * 3^2 * 5^1 * 7^1 * 11^1\)
288 = 2 * 12 * 12 = \(2^5 * 3^2\)

To find the GCF take all the common terms and take their lowest power in all of the above.

=> GCF(6930,288) = \(2^1 * 3^2\) = 18

So, Answer will be B

Method 2: Common Division Method

3 | 6930, 288
-----------------
3 | 2310 , 96
-----------------
2 | 770 , 32
------------
__| 385, 16

=> GCF = Product of Common factors = 3*3*2 = 18

So, Answer will be B
Hope it helps!

To learn more about LCM and GCD watch the following videos