Choice B reason: Risperidone is well-known for causing significant hyperprolactinemia. It strongly antagonizes dopamine D2 receptors in the tuberoinfundibular tract. Since dopamine normally inhibits prolactin release, blocking it causes prolactin levels to rise sharply, leading to side effects such as galactorrhea, gynecomastia, and menstrual irregularities in patients, regardless of gender.

Choice C reason: Zyprexa (Olanzapine) is a second-generation antipsychotic that generally has a lower risk of causing sustained hyperprolactinemia compared to Risperidone. While it may cause transient elevations in prolactin, it is more commonly associated with metabolic side effects such as significant weight gain, dyslipidemia, and increased risk of type 2 diabetes.

Choice D reason: Haldol (Haloperidol) is a potent first-generation antipsychotic that certainly can cause increased prolactin. However, in modern clinical practice, when a patient specifically presents with breast leaking on a newer regimen, Risperidone is the most "notorious" culprit among the atypical agents for this specific dose-related endocrine side effect.