According to an Article the Wall Street Journal,"The Big Car

According to an article the Wall Street Journal,"The big car makers are pushing a wide array of new technology into production,responding to relentless competitive pressure,
Rising energy prices and consumer demand for better safety.
Source: Joseph B.White,"Ford,GM Eye Shift in Buying Habits," Wall Street Journal,May 22,2006.
Which of Porter's competitive forces does this statement allude to?

A) the threat of competition from new entrants
B) competition from foreign auto manufacturers
C) competition from existing firms within the industry
D) competition from substitute products from outside the industry