The ability of sugar to dissolve in water is called

Solution

Explanation:

An example of this type of mixture is sugar in water. Here the sugar dissolves fully to give a clear solution. In this example, sugar is the solute and water is the solvent.

solubility

Explanation:

your question is incomplete

explanation:

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."