I am no expert but I think the correct answer is C.
Answer:
62
Explanation:
31 pairs
A mule is the offspring of a male donkey (a jack) and a female horse (a mare). A horse has 64 chromosomes, and a donkey has 62. The mule ends up with 63. Mules can be either male or female, but, because of the odd number of chromosomes, they can't reproduce.
The answer is D. It removes the microbes but does not kill them.
