D all 3 of them would be causes
Traveling to and from cities became easier. (I think thats correct)
The correct answer among all the other choices is C. The feuds between religious and secular power over investiture. The fall of the western Roman empire contributed most directly to this circumstance. Thank you for posting your question. I hope that this answer helped you. Let me know if you need more help.
Shays rebellion told the people that the Constitution was not right and they have to come together to change it and make it better.