Select the most appropriate ANTONYM of the highlighted word in the given sentence.
The CEO called for compulsory participation from each employee.

Correct option is D

Word Meaning:
Compulsory = required by rule or law; mandatory.
Synonyms: mandatory, obligatory, required.
Antonyms: optional, voluntary, discretionary.
Explanation:
• "Voluntary" means done by free will, the direct opposite of "compulsory".
Option Meanings :
Compliantly – obediently; अधीनता से
Overtly – openly; स्पष्ट रूप से
Obligatory – mandatory; अनिवार्य
Voluntary – done willingly; स्वेच्छा से