7. In the ear, just above the cochlea, there are three small semi-circular canals _____ as an organ of balance.1 poinA. that function togetherB. function togetherC. are functioning togetherD. they function together

The correct answer is A. "that function together".

Here's why:

A. that function together - This is the correct answer because the phrase "that function together" correctly modifies the noun (the three small semi-circular canals) and clearly explains their role as an organ of balance.

B. function together - This option is incorrect because it lacks a relative pronoun (like "that" or "which") to connect the clause to the noun it's modifying.

C. are functioning together - This option is incorrect because the present continuous tense ("are functioning") is not needed in this context. The simple present tense ("function") is more appropriate to describe a general fact or regular action.

D. they function together - This option is incorrect because the pronoun "they" is unnecessary. The relative pronoun "that" should be used to introduce the clause and refer back to the noun it's modifying.