Option 1 -> (A), (B) and (C) only - Incorrect, as Chembai Vaidyanatha Bhagavatar was a renowned vocalist, not a composer of the Trinity.
Option 2 -> (B), (C) and (D) only - Incorrect, as it excludes Syama Sastri who is part of the Trinity and includes Chembai Vaidyanatha Bhagavatar who is not.
Option 3 -> (A), (B) and (D) only - This correctly identifies Syama Sastri, Muthuswami Dikshitar, and Thyagaraja as the three composers.
Option 4 -> (A), (C) and (D) only - Incorrect, as it excludes Muthuswami Dikshitar and wrongly includes Chembai Vaidyanatha Bhagavatar.
Hence, Option 3: (A), (B) and (D) only -> The Trinity of Carnatic Music refers to the three legendary composer-saints: Syama Sastri, Muthuswami Dikshitar, and Thyagaraja, who lived during the 18th-19th century and revolutionized Carnatic music with their compositions. Chembai Vaidyanatha Bhagavatar was a celebrated 20th-century vocalist, not part of this Trinity -> correct