Choose a word which serves as the antonym of the word ‘pinnacle’.

The correct answer is Nadir.

Explanation:

1. Understanding the target word:
The word ‘pinnacle’ refers to the highest point or peak of something (such as success, a mountain, or career).

2. Analyzing the options:

• Nadir: This means the lowest point or the point of greatest adversity/despair. Since it represents the exact opposite of the highest point, it is the antonym of pinnacle.

• Crest: This means the top or highest part of something (like a wave or hill). It is a synonym, not an antonym.

• Apex: This means the highest point or tip of something. It is also a synonym of pinnacle.

• Steeple: This refers to a tall tower or spire on a building (often a church). It is unrelated as an antonym.

Therefore, Nadir is the correct antonym of pinnacle.