Answer:
-6
Explanation:
The given translation is

Which means that the original figure will be moved 3 units to the right and 8 units downwards.
Remember, when it comes to translations, when we subtract units to
that means the figure will be moved rightwards. And if we subtract units from
, that means the figure will be moved downwards.
So, the original figure has as vertex B(1,2). If we apply the transformation to its vertical cordinate
, we would have

Therefore, the right answer is the third choice -6.