Write the email to Rachel (you can make up an email address) that will achieve the negative-news goals of clarity, acceptance, and positive image. 
Remember that this case deliberately contains content and wording that may not be appropriate for your message, and the content will need reorganization to fit the 4-part indirect negative news pattern. Avoid copying long phrases/sentences from the case, and be especially careful with tone. Remember this message isn't only about explaining why you didn't choose the Food Bank—it's also about making Rachel feel valued/respected and showing that the process was fair.