Answer:
Your answer would be B; "they signed the contract with the first dealer and now must take the original deal."
Step-by-step explanation:
They already signed the contract with the first dealer and now the only option available to them is to take the original deal since they have already signed the contract meaning they have legal duty to that first dealer. (Legal Duty: a legally binding obligation on a contract to follow the law when doing something towards the other part. Since they have signed it is legally binding that they now take the original deal or the first deal.)