Option 1: (C), (D), (B), (A) -> Starts with "a higher consciousness" which cannot begin the sentence logically.
Option 2: (D), (A), (C), (B) -> Places (A) immediately after (D), disrupting the flow as "believe that joyful demeanour" is incomplete.
Option 3: (D), (B), (A), (C) -> Creates proper flow: "Renowned musicians and mystics believe that music acts as a tranquiliser, creating a serene and joyful demeanour in its practitioners and listeners promoting a higher consciousness that aligns them with the cosmos."
Option 4: (B), (C), (A), (D) -> Begins with (B) and ends with (D), leaving "believe that" incomplete at the end.
Hence, Option 3: (D), (B), (A), (C) -> This arrangement follows a logical progression: introducing the subject (renowned musicians and mystics), stating their belief about music's tranquilizing effect, describing the resulting demeanor, and concluding with the ultimate spiritual outcome -> correct