[
  "Add the whole numbers and fractions separately. Both fractions share the same denominator, so add the numerators and keep the denominator.",
  "Whole numbers: 3 + 4 = 7. Fractions: 5/9 + 8/9 = 13/9 = 1 4/9. Combine: 7 + 1 4/9 = 8 4/9.",
  "3 5/9 + 4 8/9 = 8 4/9. Answer: 8 4/9 (option D)."
]