For members of the seventeenth-century Ashanti nation in Africa, animal-hide shields with wooden frames were essential items of military equipment, a method to protect warriors against enemy arrows and spears.

(A) a method to protect

(B) as a method protecting

(C) protecting

(D) as a protection of

(E) to protect

A method to protect warriors against enemy arrows and spears protecting.

Option C

Explanation:

Option C is best choice because it is a phrase defining that, Ashanti nation used the equipment like shields for protecting themselves. It is not incomplete and unclear like other options.

Option B used the singular word 'method' to refer to the military equipment's and other items rather than referring to the use of such items.

Option A a method to protect is only referring to the items that doesn't make any meaning.

Option is D, are also incorrect; as " protection" in D has no noun for which it can substitute logically.

Option E is incomplete used to protect could be accepted. So that's why correct option is C