An example of thermosetting plastic, which is also a poor conductor of electricity is:
A. Polythene
B. Bakelite
C. Polyester
D. PVC

Hint: To solve this question, we must follow the following steps: identify the class of plastics that each of these plastics belong to. Then determine their physical properties and compare.

Complete Step-by-Step Answer:
Let us first discuss some basic concepts:
Thermosetting plastics are a class of plastics that cannot be reshaped or remoulded into another form factor after it is formed. To put it in simpler terms, thermosetting plastics are those plastics that become irreversibly fixed in a particular shape and just lose all their properties if they are tried to be reheated.
Another class of plastics are thermoplastics which have the exact opposite characteristics of thermosetting plastics. They can be reheated and remoulded. This gives them the flexibility of being reused in another form factor.
Now, in the given options, Polyethene and PVC, both are thermoplastics.
Polyester and Bakelite are both thermosetting plastics. But, polyester forms a group of polymers which are readily conductive to static electricity and in long time, this property can result in the accumulation of charges on the surface.
Hence, the thermosetting plastic, which is also a poor conductor of electricity is Bakelite.

Hence, Option B is the correct option.

Note: Bakelite was the first plastic made from synthetic components. It is a thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde.