Replace the underlined word in the given sentence with an appropriate synonym from the options listed below.
They gave us the impression that Clara was a cold and calculating woman, who was only after power.

The correct answer is manipulative.

Explanation:

In the given sentence, "They gave us the impression that Clara was a cold and calculating woman, who was only after power," the word "calculating" refers to someone who plans things carefully and craftily, often in a scheming or devious manner to gain an advantage for themselves.

Let's analyze the meaning of the options:

1. Manipulative: Exercising subtle, devious, or dishonest control over situations or people for one's own advantage. This is a direct synonym for "calculating" in this context.
2. Callous: Showing or having an insensitive and cruel disregard for others.
3. Unscrupulous: Having or showing no moral principles; not honest or fair.
4. Unsympathetic: Not showing or feeling sympathy or friendliness.

Therefore, manipulative is the most appropriate synonym to replace the underlined word "calculating".