Harry owns a Cadillac and a Porsche. Ryan has always wanted a Porsche and knows Harry owns one. Harry decides to sell his Cadillac and buy a BMW. A mutual friend of Ryan and Harry tells Ryan, "Harry's selling his car." Thinking Harry is selling the Porsche (he does not know he also has a Cadillac), Ryan calls Harry and says, "I'll give you $9,500 for your car." Harry, thinking Ryan is talking about the Cadillac, says, "You've got a deal." On what grounds is the above agreement open for rescission

mutual mistake

Explanation:

A mutual mistake happens when all the parties involved in a contract (two or more) are mistaken or do not know the correct information about some specific material fact that is relevant to the contract. In this case, the contract can be rescinded because Harry believes that Ryan wants to buy his Cadillac, while Ryan believes Harry is selling his Porsche.  

Since both of them are mistaken and do not know relevant material facts regarding the contract, the contract can be terminated.

the correct answer would be b, when, queen, calder hall and london.

explanation:

we always capitalize words when a paragraph or sentence is starting, when an important name is used, when a place is being written, or simply when a noun is used, etc. so in this sentence, sentence is starting from 'when', so it will be written in capital letters. secondly, queen is considered to be an important person, so it will also be written in capital letter. next, the name of the town is mentioned, i-e calder hall, which will also be written in capital letters. in the last,   city name is being used, 'london', which will also be written in capital letters. so option b is the most appropriate one.

answer may be d i think