28|d – 350| – 7000 < 0
add 7000 to each side
28|d – 350| < 7000
divide both sides by 28
|d – 350| < 250
remove absolute value term on left so the right side becomes +/-
d-350 < +/- 250
now add 250 to 350 and subtract 250 from 350
250 +350 = 600
350-250 = 100
answer is: B 100 < d < 600