Help analyzing arguments regarding the definition of reason

Hi Michael,

I need to check something about the differences between 2 definitions of the word “reason” . The definitions are:

A.
When I say that B is the reason for A,
I mean that if B wouldn’t have happened,
and also everything else in the world would stay the same,
then A also wouldn’t have happened.

on.

When I say that B is the reason for A,
I mean that B caused, or somehow responsible,
to the creation of A’s occurrence.”

I read somewhere that definition B actually gives a synonym for the word “reason” as a definition (normally it is cause and/or responsible), and definition A is good because it defines “by way of negation”.

Do you agree with this? What do you think about these definitions?