Answer:
B. high mutation rate; vaccine
Explanation:
The enormous genetic diversity of HIV is largely the result of its high mutation rate, and it has made it especially difficult to create a vaccine against the virus.
This ultimately implies that, the high mutation or replication rate of the human immunodeficiency virus (HIV) owing to its enormous genetic diversity has made it extremely difficult to develop an effective and accurate vaccine against the virus.
Hence, the human immunodeficiency virus (HIV) possesses a high error rate