The melancholy in Chien-an poetry is often tempered by a quality traditional critics called k’ang-k’ai， which connotes strength in the face of（）， a kind of fortitude.

The melancholy in Chien-an poetry is often tempered by a quality traditional critics called k’ang-k’ai， which connotes strength in the face of（）， a kind of fortitude.
A.happiness
B.challenges
C.success
D.adversity
正确答案：adversity