To find out how many costumes Scott can make, you need to divide the total amount of fabric he has by the amount of fabric needed for each costume.
Scott has 12 yards of fabric, and each costume uses \( \frac{3}{4} \) yard.
To find the number of costumes, you can set up the division:
\[ \text{Number of costumes} = \frac{12 \text{ yards}}{\frac{3}{4} \text{ yards per costume}} \]
Dividing by a fraction is the same as multiplying by its reciprocal:
\[ \text{Number of costumes} = 12 \text{ yards} \times \frac{4}{3} \]
Now, perform the multiplication:
\[ 12 \times \frac{4}{3} = \frac{12 \times 4}{3} = \frac{48}{3} = 16 \]
So, Scott can make 16 costumes. The correct answer is D. 16.