B is very pleasing in terms of colors and general aestethics but the nostrich (bird) element in B is almost unrecognisable and even confusing . A has the best bird representation out of all imo but A looks like it's missing something. C - the most original, creative and finished one, also lego connotations, vintage aestethics but for me this is not an obvious choice :) maybe bc the nostrich element sticks out of the general bounderies of the logo (cube)? There is sth unconventional in this but once you see C you will never forget or confuse it with another one, for sure.