Nice question, but ambiguous wording in the explanation - "up to " can mean either "up to and including" or "up to but not including ".
Sometimes the context makes it obvious which is meant: in "he drove his sword in up to the guard" it means "up to and not including", while in "he went up to the top of the hill" it means "up to and including". Sometimes the context doesn't make it obvious. In this explanation the context is that the reader is looking to discover whether the intent is "including" or "not including", so it is careless not to specify that.
Well, if we're being pedantic, "he went up to the top of the hill" does not use the phrase "up to". In that sentence "up" is an adverb modifying "went" and "to" is a preposition. A better example of "up to" meaning "up to and including" would be "you could win up to a million dollars."
Since the possible answers specified "up to, and including" it is clear from the overall context that "up to" in the explanation, not having ", and including" appended, means "up to but not including."