Chemistry Question on Organic Chemistry- Some Basic Principles and Techniques

Question

Which of the following fertilizers has the highest nitrogen percentage ?

Answer 1

Urea (46.6%N). % of N in other compound are : ${(NH_4 )_2SO_4}$ = 21.2%; ${CaCN_2}$ = 35.0% and ${NH_4 NO_3 }$ = 35.0 %