Question

Which verb form is used to indicate the progressive tense?

verb + -ed
be + verb + -ing
have + been + verb + -ing
have + verb + -ed

Answer 1

It shows an action still in progress. Verbs can appear in any one of three progressive tenses: present progressive, past progressive, and future progressive. The verbs in the progressive form use a form of "to be" + the present participle (an -ing verb). (It is the form of the helping verb that indicates the tense.)
Thus your answer is to be+verb+-ing
That's B