Power to summon the Houses of the Parliament is vested with:

The correct choice is: “President”

Under Article 85 of the Constitution of India, the President shall from time to time summon each House of Parliament to meet, and the gap between two sessions must not exceed six months. The President also prorogues the Houses and may dissolve the Lok Sabha, and under Article 108 summons a joint sitting. In practice the President acts on the advice of the Council of Ministers.

The Prime Minister advises on the dates but does not summon Parliament. The Speaker presides over the Lok Sabha and the Vice President is the ex officio Chairman of the Rajya Sabha; they conduct proceedings but do not summon the Houses.