A certain retailer promotes merchandise by using the following policy: At all times there is either a "manager' s sale" or a "holiday sale" or both going on. All sales are run for exactly one calendar month. In any given month, if a manager wishes to clear out a particular line of merchandise, then a manager' s sale is declared. If a holiday falls within the calendar month and there is excess merchandise in the warehouse, then a holiday sale is declared. However, there is no holiday that falls within the month of August and, in that month, the warehouse never contains excess merchandise. Which one of the following can be concluded from the passage? ["If there is not a manager's sale being run in some month, then there is a holiday sale being run in that month.", 'If a holiday sale is not being run, then it is the month of August.', 'If there is no excess merchandise in the warehouse, then it is the month of August.', "If a manager's sale is being run in some month, then there is no excess merchandise in the warehouse in that month."]