On which of the following dates should a firm expect its stock price to drop after a company's board of directors decides to pay a dividend?

The record date is when the company reviews its records to determine which shareholders are entitled to receive the dividend. It does not affect stock prices directly since the price adjustment occurs on the ex-dividend date, which is set before the record date to account for the time it takes to finalize shareholder eligibility.

The payment date is when the dividend is actually distributed to shareholders who were on record as of the record date. While this is the date when shareholders receive their cash, it does not influence the stock price drop since the price adjustment occurs beforehand on the ex-dividend date.

The declaration date is when the company announces its decision to pay a dividend and sets the record and payment dates. While this announcement may influence investor sentiment, it does not lead to an immediate drop in stock price as seen on the ex-dividend date, when the effects of the dividend payout are more directly felt.