Using context clues, determine the meaning of the bolded phrase.

sally, an excellent basketball player, was upset when the referee made what she considered to be a bad call, but her friend sandra kept her composure.

a. sandra was refusing to play anymore.

b. sandra remained in control of her emotions.

c. sandra was also angry.

d. sandra kept playing the game.

In this case, "kept her composure" means that Sandra remained in control of her emotions (B).

The word composure means "to stay calm." When Sandra remained in control of her emotions and did not become angry, she showed an example of keeping composure. 
The options A and C are opposites of the word "composure" because they are not calm actions. D also cannot be the correct choice because continuing to play a game is not relevant to how calm Sandra was.