Question

which sentence or sentences have correct parallel structure?
the president of the united states is not only the chief executive of the country but is also in charge of the military.
the president of the united states is not only the chief executive of the country but also the commander-in-chief of the military.

Explanation:

To determine correct parallel structure, we check if the elements after "not only" and "but also" are grammatically and structurally similar. In the first sentence, "the chief executive of the country" (a noun phrase) is paired with "in charge of the military" (a prepositional phrase), which is not parallel. In the second sentence, "the chief executive of the country" and "the commander - in - chief of the military" are both noun phrases, so they have correct parallel structure. The first sentence actually has an error in parallelism, but if we assume the checkmarks are correct (maybe a mis - assessment in the original), but based on parallel structure rules, the second sentence is correct. Wait, maybe there was a mistake in the initial marking. But strictly by parallel structure: the structure after "not only" and "but also" should match. In the second sentence, both are noun phrases (the chief executive...; the commander - in - chief...), so it's parallel. The first has a noun phrase and a prepositional phrase, so not parallel. But if we go by the checkmarks, maybe the intended answer is the second one (and maybe the first checkmark was a mistake). So the sentence with correct parallel structure is "The president of the United States is not only the chief executive of the country but also the commander - in - chief of the military."

Answer:

The sentence with correct parallel structure is: The president of the United States is not only the chief executive of the country but also the commander - in - chief of the military.