5. A container is filled with $\frac{3}{4}$ of pineapple juice, and this juice is evenly distributed into 5 empty cups. Then the amount of juice in each cup is ( )% of the container's capacity.
(A) 5
(B) 10
(C) 15
(D) 20
(E) 25
5. C.

The proportion of juice in each cup to the container's capacity is $\frac{3}{4} \times \frac{1}{5}=\frac{3}{20}=\frac{15}{100}$.