Answer:
the answer is (D) 1,048,576.
Explanation:
We know that each microbe reproduces itself every 15 minutes, so in one hour (60 minutes), each microbe would reproduce itself 4 times. Therefore, in 5 hours, each microbe would reproduce itself $4\times 5 = 20$ times.
Using the formula $P=2^n$, where $n$ is the number of times the population reproduces itself, we can calculate the size of the population after 20 reproductions, starting with one microbe:
$P=2^{20} = 1,048,576$
Therefore, the population of one microbe would become 1,048,576 after 20 reproductions, or after 5 hours. So the answer is (D) 1,048,576.