World war i was the first war to use many new technologies. which of the following was true of the use of chemical warfare? a. neither side utilized chemical weapons as these had been banned in 1907, prior to the beginning of the war. b. weapons such as poison gas were developed as a reaction to the stalemate that occurred throughout most of the war. c. the use of chemical weapons was very effective during the war, causing most of the casualties. d. the effects of chemical weapons were thought to be too gruesome to employ against enemy troops.