Identify A, B, C and D in the given sequence of reactions.
`2A+2B to 2AOH+H_(2)`
`S+O_(2) to C`
`C+B to D`

Options

A. A-Na, B-`H_(2)O`, C-`SO_(2)`, D-`H_(2)SO_(3)`
B. A-Na, B-`H_(2)O`, C-`SO_(2)`, D-`H_(2)SO_(4)`
C. A-K, B-`H_(2)O`, C-`SO_(2)`, D-`H_(2)SO_(4)`
D. A-K, B-`H_(2)O`, C-`SO_(3)`, D-`H_(2)SO_(3)`

Explanation

To solve the problem and identify A, B, C, and D in the given sequence of reactions, we can analyze each reaction step by step.

### Step 1: Analyze the first reaction
The first reaction is:
\[ 2A + 2B \rightarrow 2AOH + H_2 \]

Here, we see that two moles of substance A react with two moles of substance B to produce two moles of AOH (which is a hydroxide) and hydrogen gas (H₂).

- Since AOH is a hydroxide, A must be a metal that forms a hydroxide when it reacts with water. The most likely candidates for A are alkali metals (from Group 1 of the periodic table), such as sodium (Na) or potassium (K).

### Step 2: Identify B
Since A reacts with B to form AOH and H₂, and knowing that hydroxides are typically formed when metals react with water, we can conclude that:
- B is water (H₂O).

### Step 3: Analyze the second reaction
The second reaction is:
\[ S + O_2 \rightarrow C \]

In this reaction, sulfur (S) reacts with oxygen (O₂) to form a compound C. The most common product of this reaction is sulfur dioxide (SO₂). Therefore:
- C is sulfur dioxide (SO₂).

### Step 4: Analyze the third reaction
The third reaction is:
\[ C + B \rightarrow D \]

Substituting C and B into this reaction gives us:
\[ SO_2 + H_2O \rightarrow D \]

When sulfur dioxide reacts with water, it forms sulfurous acid (H₂SO₃). Therefore:
- D is sulfurous acid (H₂SO₃).

### Summary of Identifications
- A: Sodium (Na) or Potassium (K) (alkali metal)
- B: Water (H₂O)
- C: Sulfur dioxide (SO₂)
- D: Sulfurous acid (H₂SO₃)

### Final Answer
- A = Sodium (Na) or Potassium (K)
- B = Water (H₂O)
- C = Sulfur dioxide (SO₂)
- D = Sulfurous acid (H₂SO₃)