The correct answer is c) Both a & b.
Hyder Ali and his son Tipu Sultan were the rulers of the Mysore Kingdom in the 18th century. They invaded Kerala several times, in the 1760s, 1770s, and 1780s. The invasions were motivated by a desire to expand the Mysore Kingdom and to control the trade routes through Kerala. The invasions were also motivated by a desire to punish the rulers of Kerala for their support of the British East India Company.
The Mysorean invasions had a devastating impact on Kerala. The Mysore army looted and destroyed many towns and villages. They also carried away large numbers of people as slaves. The invasions weakened the power of the rulers of Kerala and made them more vulnerable to the British.
The Mysorean invasions were eventually repulsed by the combined forces of the British and the rulers of Kerala. However, the invasions left a lasting legacy of bitterness and resentment in Kerala.