Get me a glass of water, _____?

Here are the explanations for each option:

a) will you - This tag question seeks confirmation and is generally polite. It is the ,most common and acceptable choice.

b) shall you - This construction is less common in modern English. "Shall" is often used in questions about the future, but it may sound formal or old-fashioned in this context.

c) would you - This tag question is polite and commonly used in requests. It might be a suitable choice. But ‘will you’ is the best choice, if ‘will you?’ is not present in any question, then ‘Would you?’ can be the answer.

d) won't you - This tag question might suggest a bit of surprise or expectation. It's less common in this context and may not be as straightforward as the other options.

In casual conversation, options a) "will you" and c) "would you" are both commonly used and appropriate. They both seek confirmation or compliance in a polite manner. But ‘will you?’ is more common and most acceptable choice.