$\begin{array}{1 1} \text{(a) A synthetic rubber is any artificial elastomer. Natural rubber is a linear polymer of isoprene.} \\ \text{(b)A Natural rubber is any artificial elastomer. Synthetic rubber is a linear polymer of isoprene.} \\ \text{(c) Natural rubber is a man-made rubber which is produced in manufacturing plants by synthesizing it from petroleum and other minerals. Natural rubber is an addition polymer that is obtained as a milky white fluid known as latex from a tropical rubber tree.} \\ \text{(d) None of the above}\end{array} $