Excavators, Inc

Excavators, Inc. ("EI") agreed to dig a foundation for Ralph's barn for $7000. EI will be entitled to additional compensation in which situation?

A) EI discovered the backhoe it planned to use on the job required $600 in service work, and added that amount to the bill.
B) EI misjudged how long it would take to do the job, and billed Ralph for three hours' additional time.
C) EI discovered very significant underground water flow which had to be addressed, and it billed Ralph for doing so.
D) EI complained that there were no available bathrooms for its crew to use-they had to drive eight miles to a quick-mart store-and EI billed Ralph for this time.
E) In none of these situations is EI entitled to additional compensation.