Which of the following is a similarity between the us constitution and all state constitutions?
a. executives called presidents
b. bill of rights
c. requirements to local governments

Think about the rules in the US.  We have Presidents.  The Constitution has a Bill of Rights, and gives powers to the local, or state, governments.  The US Constitution fulfills all of these.

Now, let's look at the state constitutions.  What are the rules in your state?  Does your state have a president?  No--it does have an executive, but that is called a GOVERNOR.  (A is wrong.)  Does your state constitution have a Bill of Rights?  No!  (B is wrong.)

But does your state have laws that your city must follow?  YES!  C is correct!

C. Requirements to local governments