Answer : 3. "Amazon "
Explanation :

An e-commerce website is a website that allows the buying and selling of products or services online. There are many examples of e-commerce websites, which include:-

1. Amazon: Amazon is a leading e-commerce website that sells a wide variety of products across the world.

2. Flipkart: Flipkart is India's largest e-commerce website that sells electronics, clothing, books, and more.

3. eBay: eBay is an online marketplace where users can buy and sell products from each other.

4. Walmart: Walmart is a major retailer that sells products online through its website.

5. Target: Target is a major retailer that sells products online through its website.