Final answer:
The possible side effects of D2 receptor antagonist anti-emetics include drowsiness, dry mouth, increased appetite, weight gain, hypertension, and tachycardia, encompassing all options provided in the question.
Step-by-step explanation:
The possible side effects of D2 receptor antagonist anti-emetics include all of the options mentioned: a) drowsiness and dry mouth, b) increased appetite and weight gain, c) hypertension and tachycardia. These medications can have a variety of side effects because they affect the dopaminergic system which plays a role in many bodily functions such as mood, reward, and gastrointestinal regulation. It's important for patients to be aware of these potential side effects and to seek support and information regarding any mental or physical health conditions that may arise or be exacerbated by these medications.