Which one$($s$)$ of the following descriptions about Counter Variables are right? $\_\_\_\_\_.$

A$.$

A counter is a variable storing a number that is incremented by a constant value

B$.$

Counters are useful for keeping track of the number of times a user clicks a button, enters a guess, or types a password

C$.$

It takes the form of Counter $=$ Counter $+$ Constant

D$.$

There is no difference between a global variable defined as a counter and a local variable defined as a counter