Venga a nuestra casa is used for someone who should respect or who is elderly so this would be the right choice.
Ven a nuestra casa would be used to refer to maybe your close friends or people you can be casual with :)
It would definetly have to be B: prudentemente
Answer:
if you want the answer to this you should probably look it up on a teacher's resource website
Explanation:
In order of blanks left to right top to bottom:
empieza, quieren, prefiere, quieres, puedo, cierra, pienso, prefieres
