Graphite differs from Diamond because graphite is:

Question

$\begin{array}{1 1} \text{a. Greyish black in colour and bad conductor of electricity.} \\ \text{b.Slippery to touch and good conductor of electricity.} \\ \text{ c.Greyish black in colour and bad conductor of heat.} \\ \text{ d.Slippery to touch and good conductor of heat.} \end{array}$