The correct option is A Shall
'Shall' is used to offer a suggestion, make a suggestion or for obligation in formal situations. 'Should' is often used to give an opinion, make a suggestion, or to express a preference or idea. 'Will' is used to show desire, preference/choice or consent. 'Could' is used to show past ability. From the given sentence, we can infer that a polite request is being made or a suggestion is being given. So, the most appropriate answer is option A) Shall.