Question

A chemical was added to hand sanitizers and dish detergents to kill bacteria. Certain species of bacteria are no longer killed by this chemical. One likely

reason for the decreased effectiveness of this chemical is that these bacteria have
1. slower metabolic rates
2. a mutation for resistance
3. been selectively bred for survival
4. an adaptation to a different niche

Answer 1

2. A mutation for resistance

Reason: Bacteria evolve to resist what kills it therefore the most likely reason for it resisting is a mutation due to evolution.