Correct option is D
The sentence in option (d) has no spelling errors.
Correct spellings:
· Distinction – meaning "difference or contrast between similar things" (अंतर).
· Pleasure – meaning "a feeling of happiness or satisfaction" (सुख, आनंद).
· Happiness – meaning "the state of being happy" (खुशी).
Correct sentence: "To know the distinction between pleasure and happiness is an important awakening."