1. Scouring is a process in which the obtained fleece is washed to remove all the impurities like dirt, grease, etc.
2. Silk worms feed on mulberry leaves.
3. Wool is an animal fibre obtained from sheep, camel, yak etc.
4. Silk fibre is obtained from cocoons of silk worms.
Therefore,
Column IColumn II1. Scouring(e) Cleaning sheared skin2. Mulberry leaves(c) Food of silk worm3. Yak(b) Wool yielding animal4. Cocoon (a) Yields silk fibres