What form is the underlined verb in the sentence?

The dog is barking at something in the backyard.

A.

past participle

B.

present participle

C.

present

D.

past

If the underlined word is only 'barking', then the correct answer is B) present participle, because those are used to form present progressive tense, as is the case here.

A) would be 'barked'.

C) would be 'bark/barks'.

D) would be 'barked', the same as A.

The answer is B. present participle. Because it's end's in - ing.