Select the INCORRECTLY spelt word from the underlined words in the following sentence.
It is important to see school holistically, it is not a set of atomic items of rooms, library, assembly halls, canteen and playgrounds; it is all of these but in symbiotic relationship with each other, the contors of which are often far too obvious and often simply mysterious.

A

mysterious

B

symbiotic

C

contors

D

holistically