Select the correct passive form:
"They are building a house."

• সঠিক উত্তর: গ) A house is being built by them.

- Active Voice:
- They are building a house.
- Tense: Present Continuous.

- Passive Voice Structure (Present Continuous এর জন্য):
- Object + is/am/are + being + past participle (V3) + by + subject.

- A house (object) + is being + built (V3 of build) + by them
-Passive Voice: A house is being built by them.

• Other options:

ক) A house is built by them. : Present Indefinite.

খ) A house was built by them. : Past Indefinite.

ঘ) A house has been built by them. : Present Perfect.

Source: A Passage to the English Language, S.M. Zakir Hussain.