What needs to be done when the Recurring Price field is not showing on product setup?

What needs to be done when the Recurring Price field is not showing on product setup?
A . Recurring price and cost needs to be enabled on Attribute settings of the product.
B . The pricing mechanism needs to be set to pricebook and the Recurring price column needs to be filled.
C . Use of Recurring price and cost needs to be enabled on the user page.
D . Recurring price and cost needs to be enabled under Application parameters.

Answer: D