The organophosphates produce irreversible inhibition of cholinesterase because:
A. They bind to an allosteric site of the enzyme resulting in unfavourable conformation of esteratic site to bind acetylcholine
B. Regeneration time of the phosphorylated enzyme is longer than the turnover time of the enzyme molecules
C. Phosphorylation results in rapid degradation of enzyme molecules
D. They are neither metabolized nor excreted from the body