Concept:"Self-effacing" means modest and avoiding attention, so its opposite describes an overinflated sense of self-importance.
Explanation:A self-effacing person does not boast or seek the spotlight.
The word "conceited" means having an exaggerated opinion of oneself, which is the direct opposite.
"Aggressive" refers to forceful or hostile behaviour, not an attitude of modesty.
"Lousy" means poor or bad in quality, and "unfriendly" means lacking warmth, so neither contrasts with "self-effacing".
Thus, "conceited" is the word that is most nearly opposite and correctly fills the gap.
Answer:C. conceited