Adam is an apple grower in Tasmania. He grows a variety of apples to sell locally, interstate and overseas. To improve sales, Adam produces a brochure that includes descriptions of all the apple varieties he grows and his terms of supply. On 1 May, Adam sends a few brochures to Bill in Melbourne and to Ben in Sydney. Adam also encloses a letter offering to sell 200 boxes of red apples for $10 a box. In the letter, Adam promises to keep his offer open for 2 weeks, but he soon realises that the price was too low. On 8 May, Adam sends a second letter to Bill and to Ben withdrawing his offer. Bill is happy when he receives Adam's brochures and letter on 4 May and immediately sends Adam an email asking whether he could supply 100 boxes of red apples and 100 boxes of green apples for the same price. The next day, Bill sends Adam a second email confirming his order of 200 boxes of apples. Adam receives Bill's emails in his email inbox but does read them. Ben receives Adam's brochures and letter on 5 May and on the same day sends Adam a letter enclosing one of Ben's order forms with the following words on it: "Agree to buy 200 boxes. Price payable includes cost of delivery." To improve apple production, Adam arranges for Mick to install a new irrigation system on his orchard. The contract between Adam and Mick provides that Mick will do all the work required by the end of June in return for $10,000. Mick soon finds he had underestimated the amount of work involved in the installation of the new irrigation system and begins to run into cash flow problems. When Mick tells Adam he will have to stop work on the contract, Adam reluctantly says he will give him another $2,000 if he finishes the work. Mick finishes installing the irrigation system by the middle of June. For the past 12 months, Adam has delivered 10 boxes of apples every Friday morning to his daughter Annie. This saves Adam paying to keep the apples in cold storage over the weekend and gives Annie fresh apples to use to make pies and pastries to sell in her pie shop. Nothing was written down about this arrangement but for one year Adam has delivered the apples to Annie's pie shop every Friday morning and every Friday evening Annie has given her father a hot apple pie. Adam did not deliver any apples to Annie last week because he had sold them all to an overseas buyer. When Annie called to ask about the usual Friday morning delivery, Adam said: "Sorry dear, I had to give the apples to paying customers". Adam pays Mick $10,000 for installing the irrigation system but refuses to pay him the additional $2,000. Adam does not deliver any apples to Bill or to Ben. Advise Adam whether he has any obligations under the law of contract to Bill Ben Mick and Annie in these circumstances. Your advice should be supported by reference to relevant case law.