Final answer:
Grayson's net long-term capital gain is $8,970, calculated by subtracting the long-term capital loss from the net long-term capital gain.
Step-by-step explanation:
Grayson's net long-term capital gain is $8,970. This is calculated by subtracting the long-term capital loss of $2,750 from the net of the long-term capital gain of $11,720. The long-term capital gain includes $4,550 from Stock C and $7,170 from Stock D.