well, a and d are true, and b is somewhat false...
angles that are both less than 90 degrees and higher than 0 have to add up to equal 90, not just be less than 90
c, is the same thing. Straight angles are 180 degrees, but supplementary means two angles add up to equal 180 degrees, not just one
so b and c may be true, im not sure
i know that a and d are true, therefore they are not the right answer