Answer:
a) a credit to gain on the sale of investments for $15,775
Explanation:
The journal entry on the date of purchase of such shares in the books of Apple would be
Investments A/C Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Dr. 150,000
  To Cash A/C                                  150,000
(Being investments purchased for cash)
On the date of receipt of dividend:
Cash A/C (0.40 × 6000)                   Dr. 2400
  To Dividend Income                             2400
(Being dividend received recorded)
Cash A/C (4000 × 29 - 225)                      Dr. 115,775
  To Investments A/C (4000 shares × 25)                  100,000
  To Gain on sale of Investments                          15,775 Â
(Being investments sold at a profit recorded)