This excerpt is from the Declaration of Independence, adopted in 1776.
That to secure these Rights, Governments are instituted among Men, deriving their just Powers from the Consent of the Governed, that whenever any Form of Government becomes destructive of these Ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its Foundation on such Principles and organizing its Powers in such form, as to them shall seem most likely to [result in] their Safety and Happiness.
Which idea about government powers is stated in the excerpt?
a) They are assigned to separate branches.
b) They must be granted by the people.
c) They are granted to enforce laws.
d) They must be firmly protected.

They are granted to enforce laws but in the paragraph, we can also see that the people from the government are telling us that if some laws are not good and if they are destructive, other people and their right is to alter or to abolish it, and also to institute new Government.

People have the ability and their rights but only if they think that those laws are destructive for everyone.