In Salesforce CPQ, when dealing with a product that uses a Percent of Total pricing method and you want to ensure a minimum price threshold, the correct steps to take are:

Set the product's Percent of Total Constraint field to List price is minimum. This ensures that even if the calculated percent-of-total price falls below the desired threshold, the product will not be priced lower than its list price. By setting the constraint to "List price is minimum," you're effectively setting a floor price for the product.

Create a Price Book Entry of $100 for the product. This step involves setting the list price of the product to $100 in the price book. This is crucial because the Percent of Total Constraint will use this list price as the minimum price for the product. When the percent-of-total calculation results in a price lower than $100, the system will default to the list price of $100, thereby ensuring the product never falls below this minimum price point.

Hence, the correct answers are:
A. Set the product's Percent of Total Constraint field to List price is minimum.
B. Create a Price Book Entry of $100 for the product....