(D) Weak acid, neutral, strong base, strong acid
From the pH scale: A is at pH 12 (strong base), B is at pH 5 (weak acid), C is at pH 6 (neutral/near-neutral but slightly acidic — effectively neutral here), and D is at pH 3 (strong acid). The order asked is A, B, C, D → Strong base, weak acid, neutral, strong acid — which matches option (D).
Source: Chapter 2, Section 2.3
Read the order carefully — the question asks for A, B, C, D respectively. From the diagram: A ≈ pH 12 (strongly basic), B ≈ pH 5 (weakly acidic, below 7), C ≈ pH 6 (close to neutral/treated as neutral in this context), D ≈ pH 3 (strongly acidic). Match these to the options in the same A→B→C→D sequence to get option (D).