Question

question: 4 of 20 chemical weapons are toxic chemicals contained in a delivery system, such as a bomb or shell of some type. these agents can include: choking agents - chlorine and phosgene, blister agents (or vesicants) - mustard and lewisite, blood agents - hydrogen cyanide, nerve agents - sarin, soman, vx, all of the above.

Explanation:

Choking agents like chlorine and phosgene, nerve agents such as sarin, soman, VX, blood agents like hydrogen cyanide, and blister agents (vesicants) like mustard and lewisite are all types of chemical weapons.

Answer:

All of the above.