What is the difference between the base grand total and grand total attributes of the order?
A. base_grand_total is a grand total before tax is applied; grand_total is the grand total after tax is applied.
B. base_grand_total is the grand total at the moment of order submission; grand_total is the grand total at the moment of order closing.
C. base_grand_total is the grand total in the currency of the store where the order was submitted; grand_total is in US dollars always.
D. base_grand_total is in a base currency and grand_total is in the currency of the website where the order was submitted.