On December 31, 2020, Raven Company's portfolio of equity securities was valued at $1,800. The original cost of the investments in the portfolio was $1,600. Raven does not have significant influence on the investees in the portfolio. Prepare the journal entry to adjust the securities to fair value assuming that the Fair Value Adjustment account (unadjusted) has a a. Credit balance of $90. b. Debit balance of $90.