What is the officer indicating by moving his arm alternately up and down?
A)That I must stop.
B)That I must reduce my speed.Correct
C)That I must change direction.
An officer moving his arm alternately up and down indicates that we must reduce speed.
If the indication were made by swinging a red or yellow light, then it would oblige users to whom the officer directs that light to stop.
If the indication were made by swinging a red or yellow light, then it would oblige users to whom the officer directs that light to stop.