How can a pregnant woman's sti affect her unborn fetus?
a. low birth weight
b. loss of vision
c. loss of hearing
d. all of the above

The answer to the question: "How can a pregnant woman's STI affect her unborn fetus" is D: all of the above.
Different Sexually Transmitted Infections or Diseases can have different effects on an unborn fetus. For example, Gonorrhea can cause premature birth, blindness, and a joint infection. Chlamydia can cause low birth weight due to premature birth and serious eye infections. Syphilis is easily passed on to the unborn fetus. It can be fatal to an unborn baby. If the baby survives, it can cause serious problems in many of the baby's organs. 

the answer is d

It is a Common noun I believe