Explanation:

- The sentence describes a contrast between how your sister treats you in the morning and at night.

- Option 1: *Eloquent* means fluent or persuasive in speaking or writing. It doesn’t fit in the context of treatment.

- Option 2: *Awful* means extremely bad or unpleasant, which aligns with a negative behavior contrast.

- Option 3: *Exemplary* means serving as a desirable model; representing the best of its kind. This is positive and doesn't match the negative implication.

- Option 4: *Acceptable* means adequate or satisfactory, which doesn’t strongly contrast the described situation.

Correct Answer: Option 2 - Awful.