Final answer:
Prochlorperazine is the antiemetic drug that exhibits anti-5HT3, anti-H1, and anti-D2 actions, making it effective against nausea and vomiting.
Step-by-step explanation:
The drug that has anti-5HT3, anti-H1, and anti-D2 actions is E. Prochlorperazine. Prochlorperazine is part of the phenothiazine class of drugs which, besides being used for psychiatric illnesses, have antiemetic, antinausea, and antihistaminic effects. They are also known to potentiate the effects of analgesics and sedatives. These properties make it effective in treating nausea and vomiting, through its antagonistic effects on 5HT3 serotonin receptors, H1 histamine receptors, and D2 dopamine receptors.