The correct answer is: a) Nohkalikai Falls.
Nohkalikai Falls is the tallest plunge waterfall in India, with a height of 340 feet (104 meters). It is located in the East Khasi Hills district of Meghalaya, India. The falls are named after Nohkalikai, a Khasi woman who is said to have jumped to her death from the top of the falls after being betrayed by her lover.
Elephant Falls is a waterfall located in the Periyar Tiger Reserve in Kerala, India. The falls are about 100 feet (30 meters) high and are named after the elephants that are often seen in the area.
Krang Suri Falls is a waterfall located in the East Khasi Hills district of Meghalaya, India. The falls are about 150 feet (46 meters) high and are named after the Krang Suri River, which flows over them.
Seven Sisters Falls is a waterfall located in the East Khasi Hills district of Meghalaya, India. The falls are about 100 feet (30 meters) high and are named after the seven streams that flow together to form the falls.
Nohkalikai Falls is the tallest of these waterfalls and is therefore the correct answer to the question.