Which of the following words describes a state of high energy and vitality?

The term "vigor" is associated with strength, energy, and enthusiasm. When someone is described as having vigor, it indicates they possess an abundance of vitality and liveliness. This word communicates a sense of robust health and energetic preparedness, making it fitting for describing a state of high energy.

In contrast, the other words present a starkly different meaning. For instance, "torpid" suggests a state of sluggishness or inactivity, which is the opposite of high energy. "Sullen" conveys a sense of gloominess or sulkiness, lacking the vitality that "vigor" embodies. Lastly, "indelible" refers to something that cannot be removed or forgotten, typically used in contexts related to markings or memories, and does not relate to energy or vitality at all. Thus, "vigor" clearly stands out as the appropriate choice reflecting a state of high energy and vitality.