What approach should consultant take to implement OTC within the existing matrix- based recurring pricing model?

Universal communication is a digital cable leader across the United States. They have started using communication cloud for the B2B use case. One of their new requirements is One time charge (OTCs) that depend on multiple factors. Some of the factors are account related while other factors are product related. They already use matrix based pricing for their recurring price that depends on different sets of properties on product and account.

What approach should consultant take to implement OTC within the existing matrix- based recurring pricing model?
A . Add more Columns within the existing matrix for recurring charges and calculate the OTCs using that matrix
B . Create OTCs as additional products with Prices and add those products to the cart using a separate button that uses postCartitems
C . Create Apex class and hook code to calculate the price and add as a step within the pricing plan
D . Create another matrix for OTC’s and add all the attributes from Account and product as input and price as Output.

Answer: A