At the time of admission of partner, if goodwill exist in the books of account it will be written off among:

Old partners in old profit sharing ratio

The correct answer is option 4- Old partners in old profit sharing ratio.

Goodwill appearing in the books will be written-off by debiting old partners' capital accounts in their old profit sharing ratio. Thereafter new value of goodwill will be given effect by crediting sacrificing partners' capital accounts and debiting new partners' current account.