Artificial silk is also known as rayon. It is a type of fabric that closely resembles natural silk but is made from synthetic fibers. Rayon is widely used in the textile industry for its softness, breathability, and ability to mimic the luxurious look and feel of silk.

Explanation:

Rayon is the correct answer to the question "Which one is artificial silk?" Here's why:

1. Definition of artificial silk:
- Artificial silk is a term used to describe a fabric that imitates the properties of natural silk but is made from synthetic fibers.
- It is often used as a cheaper alternative to silk, offering similar qualities at a more affordable price.

2. Comparison of options:
a) Teflon: Teflon is a synthetic polymer known for its non-stick properties. It is commonly used in cookware and does not resemble silk in any way.
b) Nylon: Nylon is a synthetic fabric known for its strength and durability. It is commonly used in the production of clothing, but it has a different texture and appearance compared to silk.
c) Fibroin: Fibroin is a natural protein that is the main component of silk fibers. It is not an artificial silk but rather a component of natural silk.
d) Rayon: Rayon is the correct answer as it is a synthetic fabric that closely resembles silk. It is made from cellulose fibers derived from wood pulp or other natural sources.

3. Characteristics of rayon:
- Rayon has a soft and smooth texture, similar to silk.
- It has good breathability, making it comfortable to wear in warmer climates.
- Rayon can be dyed easily, allowing for a wide range of vibrant colors.
- It drapes well, giving garments a flowing and elegant appearance.
- Rayon is also known for its moisture-absorbing properties, making it suitable for clothing items like dresses, blouses, and linings.
- However, rayon is less durable than natural silk and can wrinkle easily.

In conclusion, artificial silk refers to rayon, a synthetic fabric that imitates the properties of natural silk. Rayon is known for its softness, breathability, and ability to mimic the luxurious look and feel of silk. It is a popular choice in the textile industry for its affordability and versatility.