Sale Securities in Excel

Final question that is driving me crazy is about Available-for-Sale Securities Entries and Financial Statement Presentation) At December 31, 2013, the available-for-sale equity portfolio for Steffi Graf, Inc. is as follows.
Security
A B C
Total
Cost
$17,500 12,500 23,000
$53,000
Fair Value
$15,000 14,000 25,500
$54,500
Unrealized Gain (Loss)
($2,500) 1,500 2,500
1,500 400
$1,100
Previous fair value adjustment balance—Dr. Fair value adjustment—Dr.
On January 20, 2014, Steffi Graf, Inc. sold security A for $15,100. The sale proceeds are net of brokerage fees.
Instructions
(a) Prepare the adjusting entry at December 31, 2013, to report the portfolio at fair value. (b) Show the balance sheet presentation of the investment-related accounts at December 31, 2013.
(Ignore notes presentation.) (c) Prepare the journal entry for the 2014 sale of security A