A constant retains its value, by definition. The value of a variable may be changed in the course of a program. A variable may take on any value that is allowable for either a string or numeric constant.

Unlike some other programming languages $($e$.$g$.$ FORTRAN$),$ the type of variable is not determined by the name or any kind of declaration. Variable names are in the format of $1$ alphabetic character, followed by any number of other alphanumeric characters. Here are some examples of acceptable variable names:

A ABCA$12$A$0$

If a variable is set equal to a string value, such as $"$##$$",$ it will be a string variable. The very

same variable Question:

A$.$ B$.$ C$.$ D$.$ E$.$ F$.$ G$.$ H$.$

may be converted to a numeric variable by setting it to a numeric constant. Which of the following variable names can have a string value?

STG

S$3$

I

A and B $($above$)$

A and C $($above$)$

B and C $($above$)$

A$,$ B and C $($above$)$ None of the above.