Answer:
C. The lines of competition are clearly defined in the more established industries, unlike the Internet where they are blurred and indistinct, as companies that compete
Explanation:
The first one is also correct, but it is a little bad for reading. D has a spelling error, and "companies competing" in B are a little blurred. All, except last, are correct. However, considering arrangements, the 'C 'option is the best.
Collision between fast moving particles
I think it is Index Match?
