Which of the following is transferred to Realisation Account?

Patents Account

The correct answer is option 3- Patents Account.

Patent is an intangible asset so it is transferred to realisation account.

For transfer of assets-
All asset accounts excluding cash, bank and the fictitious assets, if any are closed by transfer to the debit of Realisation Account at their book values. It may be noted that sundry debtors are transferred at gross value and the provision for doubtful debts is transferred to the credit side of Realisation Account along with liabilities. The same thing will apply to fixed assets, if provision for depreciation account is maintained.
  Realisation A/c Dr.
   To Assets (Individually) A/c