Please explain to me why the first categorized items A are elastic and the second categorized items B are inelastic (not elastic).

A. The following are five examples of items that are elastic:

1. Objects of opulence

2. Substitute goods

3. Products that have near alternatives

4. Products for which there are a number of comparable alternatives

5. Products having a demand that is not elastic

B. The following are some instances of things that are not elastic:

1. Critical Elements

2. Products have a demand that is not elastic

3. Products for which there are few alternatives

4. Products for which there are no suitable alternatives

5. Veblen products