Question

A thin red border indicates the active cell. (True or False)

Answer 1

It is false that a thin red border indicates the active cell. As a matter of fact, an active cell is indicated by a thin green border. That means that you have clicked that particular cell, and that it is activated, so that you can use it and write whatever you want there. Usually, even in the real world, green means that something is active, and red that it is inactive.