“Quintessence” means the purest and most perfect form of something.
Let’s analyze the spelling:
(A) “Quintessance” – incorrect; “ance” is wrongly used.
(B) “Quintessence” – correct spelling.
(C) “Quintesance” – missing an “s”.
(D) “Quintassence” – extra “a”, incorrect.
Therefore, option (B) is the correctly spelt word.