If the weather is fine, Xiao Liu will go on an outing, if his wife does not go with him, Xiao Liu will not go on an outing; if the unit is in a hurry, Xiao Liu will not go on an outing; if today is not Saturday, Xiao Liu will not go on an outing. Assuming the above statement is correct, then if Xiao Liu goes on an outing, he cannot determine which of the following is correct? ['Wife and Xiao Liu go outing together.', 'Fine weather.', "Xiao Liu's unit has no urgent matters.", 'Today is Saturday.']