The answer to your question wold be that the sentence that shows correct capitalization is the following one: At the White House reception, the president and vice president both looked great in their formal attire.
"White House" is capitalized because it is a proper name. In English, proper nouns, that is, words describing a specific thing or entity are capitalized. However, "president" and "vice president" should not be capitalized because, in this case, they are not followed by the names. You should only capitalize titles when they come directly before a person's name, as in "President Barack Obama".
