Answer:
4 to 3 =aka 4:3 or 16 to 12 aka 16:12 probably 9:6 or 9 to 6
Explanation:
if you go through what 16 and 12 are connected to then you should be able to see how they connect
or
There are 9 squares and 6 circles what is the simplest ratio of circles to squares probably 9:6 or 9 to 6