Which one of the following statements about glycogen is correct?

• A
  It is a disaccharide stored in liver which can react with ammonia to form proteins.
• B
  It is synthesised in the liver and takes part in the formation of bile and lipase,besides being a source of energy.
• C
  It is a polysaccharide which is synthesised and stored in liver cells.
• D
  It is synthesised in blood and stored in liver and muscles to provide glucose in times of need.