Explanation:

Recently, the Coal India Subsidiary-Western Coalfields Ltd (WCL) has launched a surveillance system called WCL EYE for monitoring its mining operations and a mobile application named SAMVAAD to connect with its employees and stakeholders. And opened 3 new coal mines in Maharashtra and Madhya Pradesh having combined annual production capacity of 2.9 million tonnes (MT). The three mines which WCL has opened, are Adasa Mine, an underground to open cast mine, in Nagpur Area of Maharashtra, Sharda underground Mine in Kanhan Area and Dhankasa underground mine in Pench Area of Madhya Pradesh. Hence option 4th is correct.