Select the most appropriate option to fill in blank number 1.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. essential.
"Essential" fits because the sentence emphasizes the importance of upgrading higher education.
"Essential" means absolutely necessary or extremely important.
Meaning of the other options:
Unrequired: Not necessary.
Deserving: Worthy of something.
Fulfilling: Giving satisfaction.
Hence, the chosen option is correct.