Read the given passage.
'' Manipur today is composed of two distinctive geographical terrains: the valley and the hills. Before independence, the valley was under princely rule and the hill areas were relatively autonomous, mainly inhabited by the tribal population. In 1891 the British established their I control over the region though the king continued to rule the kingdom. The kingdom of Manipur signed a merger agreement with India in 1949 and Manipur was made a part of India. This agreement was disputed by many tribes which argued that they had been autonomous and did not agree to be a part of India.''
Answer the following questions.
a) When did the British establish their control over the Manipur?
b) When has Manipur signed a merger agreement with India?
c) Name the two distinctive geographical terrains of Manipur.