It’s a, b, and e because for a, 3 times 6 equals 18 making 3 a factor, for b 187 divided by 17 equals 11 making it a divisor of 187 and 52 divided by 17 makes 3.0588… which doesn’t make 17 a divisor for 52, for e 20 times 8 makes 160 which makes 8 a factor