Medical doctor: Sleep deprivation is the cause of many social ills, ranging from irritability to potentially dangerous instances of impaired decision making. Most people today suffer from sleep deprivation to some degree. Ttherefore we should restructure the workday to allow people flexibility in scheduling their work hours. Which one of the following, if true, would most strengthen the medical doctor's argument? ['Employees would get more sleep if they had greater latitude in scheduling their work hours.', 'The primary cause of sleep deprivation is overwork.', 'More people would suffer from sleep deprivation today than did in the past if the average number of hours worked per week had not decreased.', 'Individuals vary widely in the amount of sleep they require.']