Final answer:
The most appropriate phrase to fill in the blank is 'la cancha'.
Step-by-step explanation:
The most appropriate phrase to fill in the blank is A. la cancha. The sentence would then read, 'Jugamos al tenis en la cancha'. 'Cancha' is the Spanish word for 'court' or 'field', and in this context, it refers to the tennis court. It is the correct term to use when saying that you play tennis.
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