Why did people value silphium?

It was the essential item of trade from the ancient North African city of Cyrene, and was so critical to the Cyrenian economy that most of their coins bore a picture of the plant. The valuable product was the plant's resin (laser, laserpicium, or lasarpicium).

Silphium was a plant that was used in classical antiquity as a rich seasoning and as a medicine. It was the essential item of trade from the ancient North African city of Cyrene, and was so critical to the Cyrenian economy that most of their coins bore a picture of the plant. The valuable product was the plant's resin.

i can't beat you to a pulp if i'm not close enough.

i believe the answer is d.