Final answer:
Horizontal gene transfer in microbes leads to increased genetic diversity, which is beneficial for acquiring new adaptive traits and enhancing resistance to antibiotics, ensuring their survival in diverse environments. The correct option is A.
Step-by-step explanation:
For a microbe, a beneficial outcome of horizontal gene transfer is a) Increased genetic diversity. This process allows microbes to acquire new genes from other organisms, which can confer advantages such as enhanced resistance to antibiotics, the ability to utilize new food sources, and increased adaptability to changes in the environment.
Horizontal gene transfer contributes to the evolution of microbes and plays a key role in the spread of antibiotic resistance among bacterial populations. It is a mechanism that helps maintain a high level of genomic diversity within microbial communities, which is crucial for their resilience and ability to occupy various ecological niches.