{
  "correct_letter": "A",
  "correct_formula": "ΣM_ext = 0",
  "annotation": "Environment: g=9.81, F_drag=!=0",
  "choices": [
    "ΣM_ext = 0",
    "λ = h/(m·v)",
    "τ_net = Σ(F_i·r_i·sinθ_i) · e^(-μ·t)",
    "G = m·g"
  ],
  "correct_index": 0,
  "physics_type": "AtRest",
  "seed": "AtRest|NewtonsFirstLaw/AtRest/5",
  "is_realworld": true,
  "dropped_wrong_formulas": [
    "F_drag = (1/2)·C_d·ρ·A·v²"
  ]
}