Select the most appropriate option that can substitute the highlighted segment in the given sentence.
My cousin works day and night to achieve success in life.

Correct option is B

The correct substitution of the highlighted segment is (b) around the clock.
Explanation: The idiom around the clock means continuously, without stopping, or 24/7. (Hindi: दिन-रात, बिना रुके) It perfectly fits the context of the sentence.
Example: The emergency services work around the clock to assist those in need.
Meanings of other options:
· Vale of tears: A life full of struggles and sadness (Hindi: दुखों का संसार).
· Great dealing: Not a proper idiomatic expression.
· A handful: Something difficult to manage (Hindi: मुश्किल काम या व्यक्ति).