Which of the following systems of rocks provides maximum amount of coal in India?

Which one of the following rock systems in India is the main source of coal deposits?

Which of the following rock systems in India is the latest one?

Which of the following geological systems of rocks contain a rich reserve of iron ore in India?

Which of the following rocks contain coal and petroleum?

Which one of the following is the appropriate reason for considering the Gondwana rocks as most important of rock systems of India?