Final answer:
The increase in value resulting from improved usability and joining contiguous lots under single ownership can be defined as a well-established reputation for slashing prices in response to new entry.
Step-by-step explanation:
The definition that most appropriately applies to the increase in value resulting from improved usability, where one or more contiguous lots are joined together under single ownership, is d. A well-established reputation for slashing prices in response to new entry. This definition refers to a situation where a business has built a strong reputation for offering low prices in response to competition, which increases its value. An example of this is a retail store that consistently lowers its prices whenever a new competitor enters the market