Nello Ottonelli did the first recorded cave dive in 1878.
He wore heavy boots. The heavy boots most likely
helped to

lower him into the cave in the water so he/she wont have to swim and waste oxygen by exhaustion

Explanation:

i hope this helps

answer; (d) i believe the best answer is ; ///people said that man could not fly, but in 1903, orville and wilbur wright made the first sustained powered flight in a heavier- than-air machine;

the most appropriate strategy would be to do a questions and answer type speech.