Urea Is the Main Nitrogen-Containing Substance Secreted in the Urine

Urea is the main nitrogen-containing substance secreted in the urine of mammals. It is used as a fertilizer and in many industrial processes. Urea, with the chemical formula CO(NH₂) ₂, has two amino groups (NH₂) bonded to a carbonyl group (C=O) . Urea has three resonance Lewis structures that complete the octet for all the atoms. Which statements about these structures are correct?
I.All are equivalent.
II.All are nonequivalent.
III.Two are equivalent, and one is nonequivalent.
IV.The formal charges on all the atoms are zero in at least one structure.
V.The nitrogen-carbon and carbon-oxygen bonds all have double-bond character.

A) III and V
B) I and IV
C) II and IV
D) I and V
E) III, IV, and V