Scope quiz in methods section

The last question of the scope quiz gives the first answer as a correct response, I believe this is because it means to say that you would replace the a=10 with a new function
Def a
a=10
end

However the way the answer currently is stated it could be seen to mean you would define that function a -> then have an assignment of a=10 -> and then run the initial code- which runs in to the issue of the replacement function you wrote being given a new assignment -> of 10
In the global scope.

If I am understanding this incorrectly though I would appreciate explanation of where I am going wrong.