A political party makes major ideological adjustments to its platform at a national convention, altering the party's position to support single-payer universal healthcare.

Which of the following would be the most likely to prompt this shift?

~A changing public view of health care as a basic right in modern society

~A political need to attract unaffiliated independent voter to win critical races

~A rising public rejection of for-profit healthcare due to poor economic conditions

~A political threat posed by a single issue third party campaign for universal healthcare.

(It is not B, and I am stuck between A and C. A makes sense because it is at a convention, and many could see it s a basic right, but would that prompt a large shift in a political view? C makes sense because many would like healthcare cheaper, and ending for-profit would make this possible.)

Thanks!