Which single factor is tended to have been considered by the author as the most important in the development of man

A．Write Daisy a note of apology.,
B．Return Daisy’s notes in a few days.
C．Apologize when Daisy is less angry.
D．Let her talk to Daisy about the situation.

A．It changes the body’s metabolism through rapid weight gain.
B．It tricks the body into responding as if it were in a different time zone.
C．It promotes increased alertness by adding snacks to the diet.
D．It builds resistance to illness by increasing intake of vitamins.