Jessica is managing an e-commerce web application in AWS. The application is hosted on six EC2 instances. One day, three of the instances crashed; but none of her customers were affected. What has Jessica done correctly in this scenario?
- A. She has properly built an elastic system.
- B. She has properly built a fault tolerant system.
- C. She has properly built an encrypted system.
- D. She has properly built a scalable system.
