**Core Concept**
Prolactinomas are pituitary adenomas that secrete prolactin, a hormone involved in lactation and reproductive functions. The management of prolactinomas depends on their size, symptoms, and the risk of causing hypopituitarism or visual field defects.

**Why the Correct Answer is Right**
Treatment of a 7 mm prolactinoma is generally medical management with dopamine agonists, such as cabergoline or bromocriptine. These medications inhibit the secretion of prolactin and can induce tumor shrinkage. The mechanism of action involves binding to dopamine receptors in the pituitary gland, which leads to a decrease in prolactin secretion and a subsequent decrease in tumor size.

**Why Each Wrong Option is Incorrect**
* **Option A:** Surgery is generally reserved for large or invasive prolactinomas, or when medical management fails. A 7 mm tumor is typically too small for surgical intervention.
* **Option B:** Radiation therapy is used for prolactinomas that are resistant to medical management or have caused significant hypopituitarism. It is not the first-line treatment for a 7 mm tumor.
* **Option C:** Somatostatin analogs, such as octreotide, are used to treat acromegaly and certain neuroendocrine tumors. They are not typically used to treat prolactinomas.

**Clinical Pearl / High-Yield Fact**
Dopamine agonists are the first-line treatment for most prolactinomas, as they are effective in reducing prolactin levels and tumor size, and have a favorable side effect profile.

**Correct Answer: C. Bromocriptine.