According to Kosters theory of fun, Tic-Tac-Toe stops being fun (for most people who have played it enough) because:

A. Our skill has exceeded its challenges

B. It provides few tactile pleasures

C. It doesnt engage significant themes

D. It was never fun enough

E. We have fully grasped its patterns

Please indicate (1) which of the multiple-choice answers is the correct one and (2) why you chose that answer. You are being graded primarily on the understanding you demonstrate of the material, not on which choice you make.