Who is best

Information processing theories are known to break intelligence down into various basic skills that people employ to take in information,process it and then use it to reason and solve problems.Who is best known for propounding such theory?

Select the most appropriate option to substitute the underlined segment in the given sentence. Each dancer performed very well that it was difficult to judge who the best was. (a) such well that (b) so well that (c) No improvement (d) such very well that