The underlying principle of the current rate method is:

A$.$ assets and liabilities should be translated based on their maturity.

B$.$monetary balance sheet accounts should be translated at the spot rate; nonmonetary accounts are translated at the historical rate in effect when the account was first recorded.

C$.$monetary accounts are translated at the current exchange rate; other accounts are translated at the current exchange rate if they are carried on the books at current value; items carried at historical cost are translated at historic exchange rates.

D$.$ all balance sheet accounts are translated at the current exchange rate, except stockholder equity. $=$ THIS IS THE ANSWER