For each of the following pairs, determine which business is more likely to operate in a contestable

Question:

For each of the following pairs, determine which business is more likely to operate in a contestable market, and explain why.
a. The only clothing store in a small town vs. the only natural gas provider in a small town
b. The only clothing store in a small town vs. the only cable TV provider in a small town? (What recent technologies make part b different from part a?)
c. De Beers diamond mining vs. H&R Block tax preparation services