Final answer:
The 43-year-old man recently diagnosed with lung cancer is likely experiencing sadness and grief, which he may express by crying or appearing withdrawn. Anger and frustration are also common reactions, but happiness, relief, excitement, and optimism are generally not typical emotions following such a diagnosis.
Step-by-step explanation:
When a 43-year-old man with a history of cigarette smoking is diagnosed with lung cancer, the variety of emotions he might experience are complex and personal. However, based on the psychological model introduced by Elisabeth Kübler-Ross, the medical assistant understands that emotions associated with a cancer diagnosis often include sadness, grief, denial, anger, bargaining, depression, and acceptance, but not typically happiness, relief, or excitement. In this case, given the provided options, the most likely emotions the patient might be experiencing are sadness and grief; the patient may express these feelings by crying or appearing withdrawn (option c). It is also common for patients to experience and express anger and frustration, displaying irritation or short temper (option a); however, options involving happiness and relief (option b) or excitement and optimism (option d) would be atypical in this context.