**Core Concept**
The congenital rubella syndrome eradication program aims to prevent congenital rubella syndrome, a condition that occurs when the rubella virus infects a pregnant woman, causing birth defects. The program prioritizes vaccination to prevent this condition.

**Why the Correct Answer is Right**
The first priority for rubella vaccination is offered to young women of childbearing age, particularly those in the 15-49 years age group. This is because rubella infection during pregnancy can lead to congenital rubella syndrome, and vaccinating this age group can prevent this condition. The rubella vaccine is especially important for women who are planning to become pregnant or are already pregnant, as it can prevent the transmission of the virus to the fetus.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the age group that is at highest risk of congenital rubella syndrome.
**Option B:** This option is incorrect because it does not prioritize vaccination for women of childbearing age, who are at highest risk of transmitting the virus to their unborn child.
**Option C:** This option is incorrect because it does not specify the age group that is most likely to become pregnant and be at risk of congenital rubella syndrome.

**Clinical Pearl / High-Yield Fact**
The rubella vaccine is a live, attenuated vaccine that is effective in preventing rubella infection and congenital rubella syndrome. However, it is not a substitute for contraception, and women should still use effective birth control methods to prevent unintended pregnancy.

**Correct Answer: C. Young women of childbearing age.