In starvation, nitrogen is carried from muscle to liver and kidney by: (A) Alanine, (B) Aspartic acid and Serine, (C) Glycine, (D) Asparagines
Answer is A. Transport of alanine from muscle to liver (glucose-alanine cycle) has two functions :-

Providing substrate for gluconeogenesis
Transport of ammonia (NH4+) to liver for urea synthesis