A silk saree and a nylon saree, both of same length are put to dry under the sun. Which one will dry faster? 

Silk saree is a natural fiber and nylon is a synthetic fiber. Synthetic fibers do not contain hollow spaces in between. Thus water molecules can't enter into nylon saree as in silk saree. Thus nylon saree will dry fast than silk saree.

A synthetic textile fiber created by man without the use of any natural raw materials is nylon fabric. Nylon is produced using dicarboxylic acid and diamine as raw materials. These polyamides can be used to create textiles. It is extremely elastic and strong. Fabrics made of nylon dries quickly and are water resistant. It is hydrophobic and has higher impact resistance. Since they have a very narrow intermolecular gap and a strong intermolecular force of attraction, nylon fibers cannot absorb water because the intermolecular gap is too small. Nylon absorbs water at a rate of 3.5%. Sericulture is the practise of producing silk from silkworms, which is a natural fibre. Silk textiles, which are made of proteins by nature, offer good absorbency and outstanding sheen. Even in hotter environments, silk clothing is pleasant due to its ability to absorb moisture. Typically, it can absorb 11% of its weight in moisture. Thus, nylon absorbs relatively little water, causing nylon sarees to dry out more quickly in the sun than silk sarees, thus it is not recommended to wear nylon or synthetic clothing during hot weather.

Hence, option B is correct.