What Role Do Debates Play in Modern Campaigns

What role do debates play in modern campaigns?

A) They are especially important for independents and candidates from minor parties who may not have enough financial resources for television advertising.
B) The debates provide an invaluable opportunity for frontrunners to work on developing their message.
C) With the growth of television and Internet advertising, few voters watch debates so they are becoming increasingly rare.
D) They rarely cover new ground but remain popular because they show presidential candidates up close under sustained pressure.