The correct answer is C. 47%.
Urea is a chemical compound with the formula CO(NH2)2. It is a white, odorless solid that is produced in the liver from ammonia and carbon dioxide. Urea is the main component of urine and is also used in fertilizers and other industrial applications.
The percentage of nitrogen in urea can be calculated by the following equation:
%N = (N/M) x 100
where N is the mass of nitrogen in the compound and M is the molar mass of the compound.
The molar mass of urea is 60.06 g/mol. The mass of nitrogen in urea is 28.02 g/mol. Therefore, the percentage of nitrogen in urea is:
%N = (28.02/60.06) x 100 = 47%
Option A is incorrect because it is the percentage of oxygen in urea. Option B is incorrect because it is the percentage of carbon in urea. Option D is incorrect because it is the percentage of hydrogen in urea.