Answer:
Nadaremos en la piscina would be the correct answer.
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Step-by-step explanation:
Nadamos is more than one person but the it’s past tense. Nadaremos is used as a future tense form and it’s also used if there is more than one person. For example, nadaremos en la piscina.(We are going to swim in the pool). You can also use ‘vamos a/..*nadar*’ but it’s more preferably to use nadaremos a la..*piscina*
I hope this helps :)