What action does 'falter' describe?

The term 'falter' refers to a lack of confidence or stability, resulting in a wavering or stumbling action. When someone falters, they may hesitate or show uncertainty, often due to self-doubt or a challenging situation. This can manifest in physical movements or in decision-making processes where a person may stop or slow down in their progress because they are second-guessing themselves or feeling intimidated.

This aligns perfectly with the notion of losing confidence, making B the correct interpretation of the term. In contrast, the other options present actions that do not accurately convey the meaning of faltering. Achieving success depicts a strong, confident action, engaging in deceit suggests a deliberate act of trickery, and expressing joy excessively indicates an exuberant emotional state, none of which align with the core idea of hesitancy or uncertainty that 'falter' embodies.