First lest translate the possible answers.
A¿que me recomindas? = What do you recommend me?
B.¡se me hace agua la boca! = This is an expression to communicate that something is delicious
C.¡que se repita! = let it happen again or lets do it again
D.¿Estas listo para ordenar? = do you want to order? or are you ready to order?E.A la orden = It is an expression to respond or indicate that one is available to the other person.
Answer:
1. you are an employee in a store and a customer says "thank you", so you answer - (E) " a la orden"
2. in a restaurant you don't know what to order so you ask the waiter - (A) " ¿que me recomiendas?"
3. The waiter handed you the menu and asked if you want to order - (D) "¿estas listo para ordenar?"
4. after dinner at the restaurant you are very happy for the food and service received at the site for what you say - (C) "que se repita"
5.you're hungry and you see some desserts that look delicious, so the expression is- (B) "¿se me hace agua la boca!"