which sentence or sentences have correct parallel structure? before becoming involved in animal - assisted…

which sentence or sentences have correct parallel structure? before becoming involved in animal - assisted therapy, a dog must be able to sit on command, stay until released, and obey other basic instructions. before becoming involved in animal - assisted therapy, a dog must be able to sit on command, to stay until released, and to obey other basic instructions.

which sentence or sentences have correct parallel structure? before becoming involved in animal - assisted therapy, a dog must be able to sit on command, stay until released, and obey other basic instructions. before becoming involved in animal - assisted therapy, a dog must be able to sit on command, to stay until released, and to obey other basic instructions.

Answer

Brief Explanations:

Parallel structure requires consistent grammatical form. In the first sentence, "sit on command", "stay until released", and "obey other basic instructions" are all verb - phrases. In the second sentence, "to sit on command", "to stay until released", and "to obey other basic instructions" are all infinitive phrases. Both maintain parallelism.

Answer:

"Before becoming involved in animal - assisted therapy, a dog must be able to sit on command, stay until released, and obey other basic instructions." and "Before becoming involved in animal - assisted therapy, a dog must be able to sit on command, to stay until released, and to obey other basic instructions."