The formulas were part of the performance to allow the audience a moment to breathe while the singer could think about the next part of the story. These formulas for different aspects of culture such as greeting guests, eating meals, etc.
Length, fluidity and relevance.
I would belive A is your answer sorry if that is wrong
"He exercised while I watch television." because the tenses of the verbs don't match--"exercised" is past tense and "watch" is present.
