Select the most appropriate option to fill in blank number 5.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. is gained.
The correct choice, "is gained," is used because it indicates a general truth about deep sleep.
The passive construction "is gained" fits the sentence, suggesting that real happiness is continuously or inherently attained during deep sleep.
This aligns with the context, where the passage explains the state of happiness during sleep as a consistent experience, not a one-time or past event.
The other options don’t convey this ongoing or habitual sense.