Write 0.21 as a percent.

A) 0.21%
B) 2.1%
C) 210%
D) 21%
is the answer D

lets see: .21 is twenty-one hundredths, right? then it must be 21 per hundred, or 21 percent.

To write a decimal as a percent, you need to move the decimal point two places to the right and add a "%" sign.

In the case of 0.21, when you move the decimal point two places to the right, you get 21. So, the answer is 21%.

Therefore, the correct answer is D) 21%.