The correct option is B Everyone
Here, 'everyone' as an Indefinite Pronoun is correct because it implies every person; all people. Here, every person is going to the party.
'All' is incorrect because it is used with singular nouns showing something has been happening for a whole period of time.
'Every' is incorrect because it is used with singular nouns to refer to all the members of a group of things or people.
'Some' is incorrect because it is used with uncountable nouns or plural countable nouns to mean ‘an amount of’ or ‘a number of’, when the amount or number is not given.