Explanation

Kashmir Shaivism, the non-dual Shaiva tradition of Kashmir, was propounded by Vasugupta (c. 9th century CE), to whom the Shiva Sutras were revealed. Abhinavagupta was its greatest later exponent and systematiser (Tantraloka), and Ramakantha belonged to the Shaiva Siddhanta tradition; neither founded Kashmir Shaivism. The answer is (A). (Cross-checked with Testbook's CDS-I 2024 solutions.)