**Core Concept**
The question revolves around the topic of breastfeeding in HIV-positive mothers, which is a critical concern in maternal and child health, especially in low- and middle-income countries. The underlying principle being tested is the risk of mother-to-child transmission (MTCT) of HIV through breastfeeding.

**Why the Correct Answer is Right**
The correct answer is based on the fact that HIV can be transmitted from mother to child through breast milk, especially during the first six months of life. This is because HIV can be present in the breast milk of HIV-positive women, and the baby may ingest the virus while breastfeeding. The risk of MTCT through breastfeeding is significant, especially if the mother's viral load is not well-controlled. In fact, the World Health Organization (WHO) recommends that HIV-positive mothers should not breastfeed their babies, except in settings where safe alternatives to breast milk are not available.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately reflect the current recommendations for HIV-positive mothers. While some studies have suggested that antiretroviral therapy (ART) may reduce the risk of MTCT through breastfeeding, the overall risk is still significant.
**Option B:** This option is incorrect because it is too vague and does not provide a clear recommendation for HIV-positive mothers. The risk of MTCT through breastfeeding is a critical concern, and a more specific answer is needed.
**Option C:** This option is incorrect because it is not supported by current evidence. While some studies have suggested that exclusive breastfeeding may be safer than mixed feeding, the overall risk of MTCT through breastfeeding is still significant.

**Clinical Pearl / High-Yield Fact**
One important point to remember is that HIV-positive mothers should not breastfeed their babies, except in settings where safe alternatives to breast milk are not available. In such cases, the benefits of breastfeeding (e.g., reduced risk of diarrhea and respiratory tract infections) may outweigh the risks of MTCT.

**Correct Answer: B. Exclusive formula feeding is recommended for HIV-positive mothers.**