The correct option is C as well as
Two people are mentioned that attend a wedding ceremony. The sentence is a combination of two sentences that according to the structure may have been 'Dan attended the wedding ceremony.', 'Betty attended the wedding ceremony.' As these are combined into the one we're given, the names are merely added in one sentence, saying that Dan and Betty went to the wedding ceremony. From the options, 'as well as' is the most appropriate compound conjunction. (compound conjunctions are phrases that link together clauses/sentence into a sentence). 'As well as' means 'in addition to', or 'and'. Hence option C is correct. 'In order that' means 'for the reason that', it expresses purpose, whereas the sentence expresses an addition, hence option A is incorrect. 'Even if' refers to contrast, where one part of the sentence is an imaginary situation that may or may not be true, whereas the given sentence is not contrast and has no imaginary situation. Hence option B is incorrect. 'As soon as' means 'immediately; at once', it's used in time-related sentences, and isn't required here as the sentence does not focus on time. This means that option D incorrect.