"A Landlord Rents Out a Small House

"A landlord rents out a small house. When the lease is due for renewal, the landlord learns that the tenant has taken a job very close to the house and is therefore unlikely to move. The landlord raises the rent $40 per month more than he was planning to do." In surveys, a large majority of respondents find this to be unfair. This is because:

A) Pricing strategies that deliberately exploit the dependence of a particular individual is considered offensive by many.
B) There are rental market laws against such large and arbitrary rent increases.
C) Such large and arbitrary increases in rent are contrary to the spirit of market competition.
D) Rental rules state that if the same tenant wishes to renew the contract, this must be renewed at the previously existing rent.