We have been given that
2 cups flour + 3 eggs + 1 tbs oil → 4 waffles
In order to make 4 waffles we need 3 eggs.
Thus, to make 1 waffle we need 3/4 eggs.
Now, in 1 dozen there are 12 waffles. Hence, to make 12 waffles we need

Therefore, 9 eggs are needed to make 1 dozen waffles.
D is the correct option.