If General Contracting is sued by Rockville for refusing to complete the job, General Contracting can have the contract discharged on an impracticability basis.
When parties to a contract agree to a contract that based on normal circumstances and due course, and one party discovers that they cannot complete the contract based on unforeseen circumstances, the contact can be ruled impractical.
General Contracting could not foresee the solid granite foundation and so they could not have known they would pay so much to complete the project. The contract can therefore be impracticable.
Find out more on impracticable contracts at https://brainly.com/question/10160005.