Answer:
Correct answer's the top one
Explanation:
Think of powers of 10. Each power is 10 times larger or smaller than the last one. So in this instance, the bacterium has a diameter of 10^-6 which is 1 millionth. And then there's the virus, which has a diameter of 10^-7 which is 1 ten millionth. So basically, take 10^-7 and times that by 10. This gives you 10^-6, which can only mean that the bacterium is 10 times bigger than the virus, which is the answer on top.