What must be added after setting a bash variable?

When you set a bash variable, using double quotes is important for ensuring that any special characters or spaces within the assigned string are properly interpreted as part of the value rather than as separate commands or delimiters. For example, if you want to assign a string containing spaces to a variable, enclosing that string in double quotes allows it to be assigned correctly as a single value.

Using double quotes prevents word splitting and preserves the integrity of the content assigned to the variable. Additionally, it allows for variable expansion within the quotes if another variable is referenced.

In contrast, the other options do not serve the same purpose in the context of variable assignment. A semicolon is used in bash to end a command, a question mark has no special significance in basic variable assignments, and the hash symbol is typically used to indicate comments. Therefore, utilizing double quotes is key for proper variable assignment in a bash script.