D. It is used to add sound effects.
Hope this helps!
Weegy face is known to be a computer generated program that was designed well by expert developers. It's a type of image that usually works whenever you use the Internet Explorer, and works most of the time on that browser.
Answer:
for (char outerChar='a'; outerChar<='e'; outerChar++){
for (char innerChar='a'; innerChar<='e'; innerChar++){
cout << outerChar << innerChar << "\n";
}
}