What is the correct syntax to include a quote character in a string definition?

To correctly include a quote character within a string in programming, the escape character must be used to indicate that the quote is part of the string rather than a delimiter for the string itself. In most programming languages, a backslash () is used as this escape character.

Option D correctly uses the backslash to escape the single quote character around "Hello World." This means that the programming environment will treat the quote as part of the string, allowing it to be included without ending the string prematurely.

In contrast, other options do not utilize the escape character correctly in the specific context of single quotes used within a single-quoted string. As such, they do not demonstrate the appropriate syntax necessary for including quote characters in the string definition under the stated conditions.