Explain the Fixed option with an example.

In Fixed Product Options, you must manually select the sub-products to add to a parent product. Here the options are pre-defined and cannot be modified by the customer. You can select a minimum and maximum number of products to be added as a sub-product.
For example, an online retailer sells customized T-shirts. One of the product options you offer is the color of the T-shirt. Within the color option, you may have several fixed options, such as:

1. Red
2. Blue
3. Green
4. Black
5. White

In this example, customers can only choose from these fixed color options for their T-shirts. They cannot input their custom color or mix different colors. The choices are already predetermined and set by the retailer.