Well, I think B would first say "Yes" and then ask a question such as "What do you have?" or "What have you got?"
It is not likely that anyone would use these sentences:
"What have you got to drink?" "What sort of drinks are there?"
These are unnecessarily redundant and wouldn't sound natural.
A could also say something such as this:Can A say: There are coke, lemonade and orange juice. No, no native speaker would use 'are' here.
( or should A say: there is some coke, lemonade and orange juice) Yes, use 'is' -- with or without the word 'some'.
"I've got coke, lemonade and orange juice."