What is the central idea of the article "A proposed mine in Alaska may bring jobs, but threaten a way of life?"

Ithink the answer to that would be b):

I'm pretty sure it's c. extremely gradual but not 100% sure though.

This would be an open primary. a closed primary people can vote only prior to election day if the party if they are registered. independent voters can not participate. there is not a wide-open primary, but there is a semi-open primary.