Question

the dog is waiting for his master to return.
past progressive present progressive future progressive

Explanation:

The sentence "The dog is waiting for his master to return" uses the structure "is + present participle (waiting)", which is characteristic of the present progressive tense. The present progressive tense is used to describe actions that are happening at the moment of speaking or around now. The past progressive would use "was/were + present participle", and the future progressive would use "will be + present participle", neither of which match this sentence.

Answer:

present progressive