Option 1 -> While Rao was indeed secretive, the passage emphasizes preservation of books, not closing the shop to the public.
Option 2 -> The passage explicitly states he sold to a longstanding customer "ensuring the books were preserved," reflecting his bibliophile nature and dedication to the books' care.
Option 3 -> Rao is portrayed as passionate about preservation, not profit-driven; he relied on word of mouth and kept a low profile rather than maximizing business.
Option 4 -> Nothing in the passage suggests mercenary motives or financial need for treatment; this contradicts his devoted, perfectionist character.
Hence, Option 2 -> The passage clearly indicates Rao's primary concern was preservation, selling to a trusted "longstanding customer" to "ensure the books were preserved," consistent with his character as a "self-taught bibliophile and perfectionist" who devoted his life to caring for antiquarian books -> correct