Berkshire Co. purchases investments in trading securities at a cost of $130 on December 15, 20X1. (This is its first and only purchase of such securities.) On December 28, Berkshire received a $15 cash dividend from the stock purchased on December 15. At December 31, 20X1, the trading securities had a fair value of $140. a. Prepare the December 15 acquisition entry for the trading securities' portfolio. b. Prepare the December 28 receipt of cash dividends entry for the trading securities' portfolio. c. Prepare the December 31 year-end adjusting entry for the trading securities' portfolio. d. Prepare the January 3, 2018, entry when a portion of its trading securities (that had originally cost $33) is sold for $36