If something (S) is very responsive to the actions of something else (E) then when that something else (E) makes a changes then the first something will also change very similiar. If someone is allergic to bees, I would say that person is very responsive to bees. Let’s say an allergic person (one sting puts them into shock) and a beekeeper who is used to bees and their stings are put in a room without any bees. If a bee hive is gently introduced into the room, the allergic person should react the most and will make it to the door very fast. You could say the allergic person is very reactive (or elastic) to bees. The bee keeper would generally not react much if at all and would be inelastic.
A) Please give your own examples of inelasticity and elasticity.