Liam highlighted the columns in the multiplication table below to find equivalent ratios. A multiplication table. In the row labeled 2, the numbers 2, 4, 6, 8, 10, 12, 14, 16, and 18 are highlighted. In the row labeled 6, the numbers 6, 12, 18, 24, 30, 36, 42, 48, and 54 are highlighted.

The same number goes into each box to make the two ratios below equivalent.

Which number goes into both boxes?
6
9
12
18