Answer:
1st one
Explanation:
Since 6 = 225, when going to 12 it would be 450, meaning the last one is wrong. when going up to 18, it would be 675, meaning that the 3rd one is wrong. It also means that the second one is wrong because it goes to 20 but has the same value as going to 18. Through process of elimination, the 1st option is correct