Imagine how the actors move (like stage right, left, upper stage, etc.)
In grammar, an interjection is a word used to display emotions, such as surprise, glee, anger, etc. In this case the word "Yummy" is being used to display eagerness to enjoy the dinner that smells so unbelievably good.
Option A, "Yummy", is your correct answer choice.
Hope that helped! =)
C. Making sure that you do not have too many simple sentences
1 Non-fiction is true writing
2 A biography based on experience or research
4 Biography
5 travel brochure