An exposure to sarin or sarin like chemical will caused the sarcoplasmic reticulum to be continuously stimulated by the continual electrical signal. This will open the calcium channels and allows the calcium ions to bind continuously with troponin. Sarin is an organophosphorus chemical which is highly poisonous. It is used as a chemical weapon of destruction.
I think it is b because it is a result of an environmental influence
It is found in the cell walls of plants.
