Which account is affected by the rule for sharing profit and loss in the deed?

Correct answer: Profit and loss appropriation account

The profit-and-loss appropriation account shows how the firm’s accounting profit is distributed among partners after arriving at net profit. Items such as interest on capital, partner salary, commission, interest on drawings, and the agreed share of profit or loss are recorded or adjusted through this account. Therefore, a deed rule about sharing profit and loss directly affects the Profit and Loss Appropriation Account. Option A is correct. The cash book records cash transactions, the purchase book records credit purchases, and a salary register is not the account used to distribute partnership profit; therefore options B, C, and D are not suitable.