**Core Concept**
Zidovudine, a nucleoside reverse transcriptase inhibitor (NRTI), is a cornerstone in the management of HIV/AIDS. While it is effective in suppressing viral replication, zidovudine therapy can be associated with several adverse effects due to its mechanism of action and metabolism.

**Why the Correct Answer is Right**
Zidovudine is primarily metabolized by glucuronidation, which results in the formation of a toxic metabolite. This metabolite can cause bone marrow suppression, leading to anemia, a common complication of zidovudine therapy. Additionally, zidovudine can also cause gastrointestinal disturbances such as nausea and vomiting, due to its direct effect on the gastrointestinal mucosa.

**Why Each Wrong Option is Incorrect**
**Option A:** Nausea and vomiting are indeed complications of zidovudine therapy, but they are not the most specific or severe adverse effects associated with this medication. While nausea and vomiting are common, they do not directly relate to the primary mechanism of zidovudine toxicity.
**Option C:** Steatosis, or fatty liver, is not a known complication of zidovudine therapy. Steatosis is more commonly associated with other medications, such as tamoxifen and certain antiretroviral therapies like didanosine.
**Option D:** Nephrotoxicity is not a well-documented complication of zidovudine therapy. Zidovudine's primary toxicities are related to bone marrow suppression and gastrointestinal disturbances, rather than renal impairment.
**Option E:** Cardiotoxicity is not a recognized complication of zidovudine therapy. While certain antiretroviral therapies can cause cardiovascular side effects, zidovudine is not typically associated with cardiotoxicity.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that zidovudine is a prodrug that requires glucuronidation to become active. This unique metabolic pathway highlights the importance of monitoring liver function and considering potential interactions with other medications that may affect glucuronidation.

**Correct Answer: B. Anemia**