Stream Launch Co.'s long-term available-for-sale portfolio at the start of this year consists of the following. Stream Launch enters into the following transactions involving its available-for-sale debt securities this year. January 29 Sold one-half of the notes of Company B for $83,220. July 6 Purchased bonds of Company X for $127,200. November 13 Purchased notes of Company Z for $231, 000 . December 9 Sold all of the bonds of Company A for $581,748. Fair values at December 31 are: B,$85,600;C,$660,000;X,$120,000; and Z, $239,000. Using the drop-downs, select the stocks included in the available-for-sale portfolio as of December 31 . Calculate the total cost and total fair value of the available-for-sale portfolio as of December 31, and calculate the amount of the required year-end adjusting entry, if any