Together with gold, it was very expensive and important wealth during the olden time a. pepper
b. salt
c. garlic
d. onion

Salt

Explanation:

Salt used to be very expensive. The reason for this is that it was illegal to produce and sell it. The price for salt at some points were acutally higher than the price of gold.

Similarly pepper was expensive in similar times, but not nearly and expensive as salt and gold was.

salt

Hope this helps!

a is the final ! : )