Question

when associating an event handler with a button click, which event occurs when you click the left button of a mouse?
button-1
button-2
button-left
button-3

Explanation:

In many programming and graphical - user - interface contexts, the left - mouse button click event is often referred to as Button - 1. Button - 2 is usually the middle mouse button and Button - 3 is the right - mouse button. "Button - Left" is not a standard naming convention for this event.

Answer:

A. Button-1