Answer:
They don't have a contract because, Although they attempted to accept the original offer within the 10 day period, they originally made a counteroffer which means that they both denied the originally offer and made an opposing offer at once. R&R cannot simply change their mind because they found out that another company offered to do it for less. Whether or not they still have a contract is entirely in Petroleum's hands. This was more of an inquiry than a rejection. However, the option contract was not supported by consideration and so revocable at will.
Explanation: