When a strong acid such as hydrochloric acid (HCl) is accidentally spilled, the safest immediate response is to neutralise it using a mild, controllable base rather than trying to simply wipe it up, since acids can damage skin, surfaces, and release irritating fumes if left untreated.

Why baking soda solution is the correct choice:

• Baking soda (sodium bicarbonate, NaHCO₃) is a weak, mild base. When added to the spilled acid, it reacts according to: NaHCO₃ + HCl → NaCl + H₂O + CO₂.
• This reaction converts the hazardous acid into harmless common salt (NaCl) and water, while releasing carbon dioxide gas (seen as gentle fizzing/effervescence), which is a useful visual indicator that neutralisation is actively taking place and helps a person judge when the reaction is nearing completion.
• Because sodium bicarbonate is only mildly basic (unlike strong bases such as sodium hydroxide), it neutralises the acid gradually and safely without a violent or highly exothermic reaction, and without leaving behind a strongly caustic residue that could itself cause burns.
• It is inexpensive, non-toxic, and readily available in laboratories, schools, and kitchens, making it a practical first-response material for acid spills.

Why the other substances are not suitable:

• Lemon juice contains citric acid, which is itself an acid — adding it to an acid spill would not neutralise anything and could compound the hazard.
• Sugar solution is chemically neutral and non-reactive with HCl; it would neither neutralise the acid nor reduce its corrosive effect, so it offers no real safety benefit.
• Vinegar is a dilute solution of acetic acid, another acid, and like lemon juice would fail to neutralise the spilled hydrochloric acid and could add to the irritation instead.

Hence, only a base capable of safely reacting with and neutralising the acid — the baking soda solution — is the correct substance to use.