Which word describes "rigors"?

The term "rigors" is often synonymous with "hardship" because it is used to refer to severe or demanding conditions that can cause stress or difficulty, whether in physical, emotional, or situational contexts. When someone speaks of the rigors of a process or experience, they typically are alluding to challenges, adversities, or the intense demands that one must endure, which aligns closely with the concept of hardship.

The other options, while they may describe different contexts or conditions, do not accurately capture the meaning of "rigors." "Energy" refers to vitality or vigor, which contrasts with the idea of facing difficulties. "Muscular stiffening" is a specific physiological response and does not encompass the broader implications of challenges or adversities. "Basics" implies fundamentals or essential elements, which does not relate to the notion of undergoing hardships or severe challenges implied by "rigors."