Answer:
Walmart’s entry into this market would represent a DRIVING FORCE originating from the COMPETITIVE environment for the automobile distributor’s industry
Step-by-step explanation:
If Walmart entered any new business they would be a driving force simply because of its mere size and tremendous market power. Driving forces can be internal (e.g. innovations, creativity, etc.) or external (e.g. economy, competition, environment, etc.).
In this case, Walmart would be an external driving force (competition) for the rest of the auto dealers simply because it would probably change the game completely. Even the largest auto dealer in the country is a tiny ant while Walmart is an elephant.
Very few companies have such an impact on the industries that they participate in, e.g. Microsoft with Windows and Office, Disney, Google or Amazon.