A$.$ does; it makes good economic sense

B$.$ does not; Tastee will charge a higher price if Sweetie enters the market and a lower price if

it doesn't

C$.$ does not; Tastee will charge a higher price regardless of Sweetie's decision

D$.$ does; Tastee will charge a lower price regardless of Sweetie's decision

E$.$ does; Sweetie would do the same thing if roles were reversed