[5] Data regarding Ball Corp.'s investment in available-for-sale debt securities follow! Cost Fair Value December 31, Year 3 $150,000 150,000 December 31, Year 4 $130,000 160,000 Differences between cost and fair values are not due to credit losses. The decline in fair value was properly accounted for at December 31, Year 3. Ball's Year 4 statement of changes in equity should report an increase of A. $30,000 B. $20,000 C. $10,000 D. $0