Which of the following best describes a person who is easily angered?

The term "irascible" specifically refers to someone who is easily provoked to anger or exhibits a tendency to become angry quickly. This adjective captures the nuanced emotional state of a person who has a low threshold for irritation or displeasure. In contrast, terms like "calm," "composed," and "patient" describe individuals who maintain their temper and composure, often exhibiting resilience to provocation or stress. Thus, the choice of "irascible" accurately highlights the characteristic of someone who is quick to anger, aligning perfectly with the requirement of the question, making it the most appropriate selection.