Which of the following words is closest in meaning to “Serene”?

Serene means calm and peaceful.

• Correct answer - calm and peaceful: it has the same meaning as Serene.
• smooth: even and without bumps - wrong, it does not mean the same as Serene.
• happy: feeling pleasure - wrong, it does not mean the same as Serene.
• alluring: powerfully attractive - wrong, it does not mean the same as Serene.