Sales is the correct form.
sale - el/ella/usted
sales - tú
salgo - yo
saleis - vosotros
Answer:
I personally would choose A.
Explanation:
A says "You ask for the bill" and B says "You ask the bill". Using "pides" helps you to say what you are asking for. I wouldn't be asking the bill... I would be asking FOR the bill.
A-) Venimos
Es la respuesta correcta