Lead is toxic, but do you know why?
a. lead is toxic mainly because it preferentially replaces other metals in biochemical reactions.
b. in so doing it interferes with the proteins that regulate blood pressure, heme production (which can lead to anemia) and sperm production.
c. lead also displaces calcium in the reactions that transmit electrical impulses in the brain, which diminishes the ability to think and recall information.

All the options are correct.

Explanation:

Lead is a p-block chemical element having atomic number 82 that belongs to the group 14 of the periodic table.

Lead is a highly toxic metal. It is a neurotoxin which affects the biological enzymes and damages the kidneys and nervous system, thus causing brain damage and behavioral problems.

It mimics and displaces other metals which act as cofactors in various enzymatic reactions. It also affects the blood pressure, heme synthesis and causes miscarriage in females and reduces the fertility in males.