Compared with the us constitution, how difficult is it to amend state constitutions?

a.) the us constitution is easier to amend.
b.) each is difficult to amend.
c.) state constitutions are easier to amend.
d.) each is easy to amend.

C.) State constitutions are easier to amend.

State constitutions are easier to amend compared with US Constitution. In the event that some parts of the State Constitution is unconstitutional based on the US Constitution, then it can be amended.

US Constitutional amendments take longer and is more tedious than the  amendment of state constitutions. That is why as of date there are only 27 amendments that has become a part of the US Constitution out of the 33 proposed amendments since 1789.