The right answer is: The maximum amount from all sources that appears safe for most healthy people.
Tolerable Upper Intake Level is the highest tolerable intake of nutrients without causing any adverse effect on an organism. It depends on the how much the individual need these nutrients.
"the amount that can be absorbed from a typical diet": False because an individual can absorb more than the Tolerable Upper Intake Level, but it will cause adverse effects.
"the maximum allowable amount available in supplement form" and "the maximum amount allowed for fortifying a food": Both are false because the Tolerable Upper Intake Level is a term which concerns individuals and not foods