Explanation:

- Option 1: President

- The power to summon each House of Parliament is vested in the President.

- The President acts on the advice of the Union Cabinet while doing so.

- Option 2: Lok Sabha Speaker

- The Speaker presides over the meetings of the Lok Sabha.

- They do not have the authority to summon Parliament.

- Option 3: Vice President

- The Vice President is the ex-officio Chairperson of the Rajya Sabha.

- They do not have the power to summon Parliament.

- Option 4: Union Cabinet

- The Union Cabinet advises the President on summoning Parliament.

- They do not directly summon Parliament.