When you said the answer is D, that refers to "They would demonstrate their weapons" Which is letter B. D says "they would learn several words of tribe's language" which does not go with your explanation

i think it’s will be a yes

`stare decisis is a legal doctrine that obligates courts to follow historical cases when making a ruling on a similar current or future case. stare decisis ensures that cases with identical facts be approached in the same way, unless overruled by the same court or a higher court such as the us supreme court. simply put, it binds courts to follow legal precedents set by previous decisions.

stare decisis is a latin term meaning "to stand by that which is decided".

i normally just use

the steam engine.

the locomotive.

the telephone.

the telegraph.

the internal combustion engine.

the rifle.

ironclad ships.

electricity/light bulb.