Final answer:
An infected burn of the arm exemplifies healing by secondary intention, where the wound heals naturally without surgical closure and fills in with granulation tissue over time.
Step-by-step explanation:
Wound healing can occur via two main processes: primary intention and secondary intention. In primary intention, the wound edges are close together and can be brought together with sutures, staples, or other methods to promote faster healing and minimize scarring. On the other hand, secondary intention healing occurs in wounds that are too extensive or contused to be immediately closed, and they heal by the gradual filling of the defect with granulation tissue, contraction of the wound edges, and subsequent epithelialization.
The answer to the student's question is: An infected burn of the arm is an example of wound healing by secondary intention. This type of wound cannot typically be closed with sutures or staples and must heal from the base of the wound upwards, which can take more time and often results in more prominent scarring.
The other options provided involve closure methods indicative of primary intention healing: abdominal wounds with staples, leg lacerations with sutures, and skin tears closed with steri-strips.