What type of punctuation is necessary to set apart nonessential appositive phrases?

commas, dashes, or parentheses

Nonessential appositive phrases can be separated from the rest of a sentence in three ways—with commas, with dashes, or with parentheses. Let’s look at example sentences that essentially mean the same thing:

The best pet in the world, a dog, will always be known as “man’s best friend.”

The best pet in the world—a dog—will always be known as “man’s best friend.”

The best pet in the world (a dog) will always be known as “man’s best friend.”

not sure maybe the subject closer to it or subject-verb agreement