For each of the following cases [(a) and (b)],
(I) State whether the study should be observational or experimental.
(II) State whether the study should be run blind, double-blind, or neither. If the study should be run blind or double-blind, who should be blinded?
(a) An investigation of whether the size of the midsagittal plane of the anterior commissure (a part of the brain) of a man is related to the sexual orientation of the man.
(b) An investigation of whether drinking more than 1 liter of water per day helps with weight loss for people who are trying to lose weight.