Which of the following statements are correct?
$(a)$ The isotope of carbon containing $7$ neutrons has natural abundance of $1.1 \%$.
$(b)$ Among the $IV$ $A$ group elements,$Sn$ has the lowest melting point.
$(c)$ Silicon is the $2^{nd}$ (by mass) most abundant element in the earth's crust.
$(d)$ Elemental carbon shows the highest electrical resistivity among the $14$ group elements.

• A
  $a, c$ and $d$ only
• B
  $a, b$ and $c$ only
• C
  $b, c$ and $d$ only
• D
  $a, b, c$ and $d$