Identify the elements W, X, Y and Z from the given information.
W : Best conductor of electricity
X : Essential component of haemoglobin
Y : Hardest natural substance
Z : Source of energy in sun and stars
| W | X | Y | Z | |
| A | Aluminium | Iron | Gold | Hydrogen |
| B | Silver | Iron | Diamond | Hydrogen |
| C | Gold | Iodine | Zinc | Helium |
| D | Copper | Mercury | Graphite | Helium |
Answer is B