Question

in the 1970s, what element was removed as an additive from gasoline? zinc copper lead palladium

Explanation:

In the 1970s, lead was removed from gasoline. Lead was used as an additive (tetraethyl lead) to improve engine performance but was found to cause environmental and health issues, leading to its phase - out. Zinc, copper, and palladium were not the additives removed from gasoline in the 1970s for this purpose.

Answer:

C. lead