Which mixture is homogeneous?

a. soil
b. granola cereal
c. salad dressing
d. milk

The correct answer is:  [D]:  " milk " .

Choice  [A]:  "soil" is incorrect;  since "soil" is "heterogeneous" {composed of many different "ingredients" .].

Same with "Choice [B]: "granola" [composed of many different ingredients—clumps of sweetened oats, raisins, coconuts, etc.].

Same with "Choice [C]:  "salad dressing".  {Notice how we usually have to "shake the bottle" ?  Composed of multiple ingredients, (e.g. oil, vinegar, and spices, or oil and other spices, and more ingredientes). 

Choice: [D]: "milk", as a liquid, is a single, well-mixed, uniform, mixture;  as such, it is "homogeneous".   Note:  "homo-" means "same".

The molecules contain like 54 of water