Select the most appropriate phrase to replace the highlighted word.
She is feeling unwell today, so she will not be going to work.

Correct option is C

The correct substitution of the highlighted words is "under the weather".
Explanation: The idiom "under the weather" means feeling unwell or sick. It is used when someone is slightly ill but not seriously sick. (हिंदी अर्थ: अस्वस्थ महसूस करना)
Example: I won't be able to attend the meeting today as I'm under the weather.
Meanings of the given options:
· Face like thunder: Looking very angry (हिंदी अर्थ: बहुत गुस्से में दिखना)
· Chase rainbows: Pursuing unrealistic dreams (हिंदी अर्थ: असंभव सपनों का पीछा करना)
· Head in the clouds: Being impractical or lost in thought (हिंदी अर्थ: वास्तविकता से दूर रहना)