To find out how many cups of milk are needed to make 144 cookies, we can first determine how much milk is needed for one cookie based on the given recipe.
The recipe calls for 2/3 cup of milk for 12 cookies. Therefore, the amount of milk needed for one cookie is:
\[ \text{Milk per cookie} = \frac{2/3 \text{ cup}}{12 \text{ cookies}} = \frac{2/3}{12} = \frac{2}{3} \times \frac{1}{12} = \frac{2}{36} = \frac{1}{18} \text{ cup per cookie} \]
Now, for 144 cookies, the total amount of milk needed would be:
\[ \text{Milk for 144 cookies} = 144 \text{ cookies} \times \frac{1}{18} \text{ cup per cookie} \]
Calculating this gives:
\[ 144 \div 18 = 8 \text{ cups} \]
So, the amount of milk needed to make 144 cookies is 8 cups.
Thus, the answer is B. 8.