What time would they stop for lunch

A．12 noon to 9 p. m.
B．9a.m. to 5 p.m.
C．9a.m. to 12 noon.

A．current medical knowledge is still insufficient
B．there are many factors influencing our decisions
C．few people are willing to trade the quality of life for the quantity of life
D．people are usually influenced by the behavior of their friends