Answer: B cautiously
Step-by-step explanation:
The context of the sentence indicates that Allisa had been preparing for the chess match diligently and had been studying new moves and strategies, as well as her opponent's weaknesses. The word "cautiously" implies that she approached her preparations with care and attentiveness, being mindful of potential challenges and risks.
In this context, the word that best completes the sentence is:
B. cautiously