Final answer:
To increase the absorption of iron when taking an iron supplement, the client should take it with orange juice, which contains vitamin C.
Step-by-step explanation:
When taking an iron supplement, the client should take it with a fluid that helps increase the absorption of iron. One fluid that aids in the absorption of iron is orange juice. Orange juice contains vitamin C, which enhances iron absorption in the body. Taking the iron supplement with orange juice can help the pregnant adolescent get the maximum benefit from the supplement.