If it is about limiting impact on your blood glucose levels, I would explore fasting liquids like water, sparkling water, coffee, tea, infusions, bone broth, etc. If you don't enjoy your tea/coffee as is, instead of milk I would add a tablespoon of double cream (it is mostly fat and would have a lot more limited impact on your blood glucose than anything containing carbs and/or protein).
As
@HSSS mentioned, all of us are individual and the impact of different foods on our blood glucose levels will be different. The testing-based decisions will allow you to individualise your diet.
I like to read my nutrition labels before I consume any food. You can look at net carb content in the food and the more carbs there are per 100g, the bigger impact on your blood glucose. I'm on very low carb diet and my rule of thumb is as follows: foods with up to 5g carbs per 100g are on my safe list, up to 10g per 100g on my use sparingly list, and above 10g per 100g on my avoid list. Out of all three drinks this would only qualify milk as my safe food. Given my use of milk (with coffee/tee) I prefer to use alternatives like double cream.
If you want to dig deeper and consider how different foods impact your blood glucose levels, you might want to read up on glycaemic index and glycaemic load. These look at how different foods impact your blood glucose compared to pure glucose and the impact considering portion size, respectively.
