Pick out the correct sentence from the options given below:

The correct answer is Option (1) → The roof of the house was blown off in the storm.

Blow off (passive) for a past event:

• Blow off means to remove by the force of the wind; its passive is "be blown off".
• A storm that has already happened needs the simple past passive: was blown off.
• "The roof of the house" shows which roof; "the house" is a particular house.
  Example: His hat was blown off by a sudden gust of wind.

Why the Other Options are Incorrect?

Option 2: The roof with the house is blown off in the storm. — Incorrect.

• The roof belongs to the house, so it is "the roof of the house", not "with".
• The present tense "is blown off" does not suit one particular storm.

Option 3: The roof of a house is blown of in the storm. — Incorrect.

• It writes "of" for "off".
• It uses the present tense for a single past event.

Option 4: The roof of a house is blown off in the storm. — Incorrect. The phrasal verb is right, but the simple present "is blown off" describes a habit or a general fact, not what happened in one storm; the event needs "was".