Select the option that can be used as a one-word substitute for the given group of words.
One who makes an active effort to promote human welfare

Correct option is A

The correct one-word for the given group of words is (a) Philanthropist.
A philanthropist is someone who actively promotes human welfare by charitable donations or activities. (मानवता के कल्याण के लिए कार्य करने वाला व्यक्ति)
Example: The philanthropist donated 10 crores to build a school.
Meanings of other options:
· (b) Philosopher: Thinker about deep questions of life (दार्शनिक)
· (c) Philanderer: A man who has casual sexual relationships (आशिक मिजाज)
· (d) Physicist: Expert in physics (भौतिक शास्त्री)
Grammatical Tip: One-word substitutions are generally nouns. Recognize them by identifying “a person who...” phrases.