Answer: 2 & 2/4 which is choice A
Work Shown:
1/4 = 0.25
2/4 = 0.5
3/4 = 0.75
2 & 3/4 = 2 + 3/4 = 2 + 0.75 = 2.75
5 & 1/4 = 5 + 1/4 = 5 + 0.25 = 5.25
Subtract the values:
5.25 - 2.75 = 2.5
Then convert back to a mixed number
2.5 = 2 + 0.5 = 2 + 2/4 = 2 & 2/4
Optionally you can reduce that 2/4 into 1/2, but it appears your teacher has chosen not to.