Excessive steroid use can lead to:

Delete the incorrect answers.
A. cardiovascular illness
B. reduced fertility
C. organ failure
D. all of the above

D. all of the above

Excessive steroid use can lead to:

A. cardiovascular illness
B. reduced fertility
C. organ failure

So, the correct answer is D. all of the above.

To determine which answers are correct, we can examine the possible effects of excessive steroid use individually.

A. Cardiovascular illness: Excessive steroid use has been associated with an increased risk of cardiovascular diseases such as high blood pressure, heart attacks, and strokes. Therefore, option A is a correct answer.

B. Reduced fertility: Steroid use can disrupt the hormone balance in the body, leading to reduced fertility in both males and females. This can manifest as decreased sperm production in males and disruptions in menstrual cycles in females. Therefore, option B is also correct.

C. Organ failure: Although steroids primarily affect hormone regulation and can negatively impact specific organs over time, the direct association between excessive steroid use and organ failure is less clear. While steroids may contribute to certain types of organ failure in some cases, it is not a common or direct consequence. Therefore, option C is incorrect.

Based on this analysis:
- Options A (cardiovascular illness) and B (reduced fertility) are correct.
- Option C (organ failure) is incorrect.

Thus, the correct answer is D.