I see your problem already. You kind of started out doing the right thing,
but you petered out for two reasons: #1. you weren't sure of what you were
doing, and #2. you tried to do it on the sheet and didn't have enough room.
Take it slow and easy.
-- Pick up your pencil again.
-- On a clean piece of paper, write down the coordinates of the three points:
(2, 1) (3, 4) (1, 3)
-- Translating the triangle down 1 unit makes every 'y'-value 1 unit less.
Above the y-value in each point, write the number that's 1 less.
(The original y-values of the points are 1, 4, and 3.)
-- Translating the triangle left 3 unit makes every 'x'-value 3 units less.
Above the x-value in each point, write the number that's 3 less.
(The original x-values of the points are 2, 3, and 1.)
-- Now you have the new points right above the original points,
and you can compare them to the choices on the sheet.
If you don't settle on choice- 'D', then check over your work.