The _____ rule states that only one transaction at a time can own an exclusive lock on the same object

When listing property, the sellers asked the salesperson to give them an opinion on the validity of the title. The salesperson should.

A. Check the title before listing the property B. Hire a lawyer and then give them an opinion C. Suggest they get some legal advice D. Have the broker give them an opinion

The firm Meek & Co., CPAs, was engaged by Reed, the president of Sulk Corp, to prepare its federal and state tax returns by March 15, Year 2, for the fiscal year ended December 31, Year 1. Meek's engagement and its fee of $20,000 were approved by Sulk's board of directors. Meek did not deliver the returns until April 15, Year 2, because Sulk did not provide Meek with the necessary information to complete the service. Sulk refuses to pay Meek. If Meek sues Sulk, Meek will

A. Prevail based on the contract. B. Prevail based on quasi-contract. C. Lose, because it breached the contract. D. Lose, because the March 15 deadline was a condition precedent to Sulk's performance.