Final answer:
In a game of blackjack, Aces are necessary for a blackjack.
Step-by-step explanation:
The answer to this question is a) Aces.
In a game of blackjack, a blackjack is a hand that consists of an Ace and a 10-point card (10, Jack, Queen, or King) in the first two cards dealt. Without an Ace, it would be impossible to have a blackjack.
Therefore, Aces are necessary for a blackjack.