Final answer:
A day is D) 2400% of an hour.
Step-by-step explanation:
To find out what percent a day is of an hour, we can use the conversion factors from day to hour. Since there are 24 hours in a day, we can say that a day is 24 times as long as an hour.
To convert fractions to percents, we can multiply the fraction by 100. Therefore, a day is 24 times 100 percent, which equals 2400 percent.
So, the correct answer is D) 2400%.