Statement ii: Mohanam is indeed an Audava-Audava raga, meaning it uses 5 notes in ascent and descent.
Statement iii: Patnam Subramanya Iyer composed many famous varnams in Carnatic music.
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Statements i and iv are incorrect:
i. Adi Tala has 1 drutam (beat cycle of 8 units), not 3 drutams.
iv. Annamacharya is not known for Tillanas; Tillanas were popularized by later composers.
Hence, the correct answer is option (A).