Answer:
b. Joan Robinson and Edward Chamberlin.
Explanation:
The Theory of Monopolistic Competition was published in 1933 in a book that was written by Edward Chamberlain who was an American economist. Also, Joan Robinson, a British economist, wrote a book called The Economics of Imperfect Competition in the same year that was about the same topic. Because of that, the answer is that the two economists associated with the development of the theory of monopolistic competition were Joan Robinson and Edward Chamberlin.