Which of the following should you do in order to add another product attribute to the condition in a shopping cart
price rule?

A.
Mark the attribute as “Use for Promo Rule Conditions” on the attribute management page in the admin.

B.
Override Mage SalesRule Model Rule Condition Product and modify the protected variable $_ruleAttributes.

C.
Create an observer on the load sales rule product attributes event.

D.
Add another child to the configuration node global/catalog/attributes_to_use_in_sales_rules.