Match the following and mark the correct option
`{:("Column I", " ""Column II"),("Fast muscle fibres",i."Myoglobin"),("Slow muscle fibres",ii."Lactic acid"),("Actin filament",iii."Contractile unit"),("Sarcomere",iv. "I-band"):}`

Options

A. A-(i),B-(ii),C-(iv),D-(iii)
B. A-(ii),B-(i),C-(iii),D-(iv)
C. A-(ii),B-(i),C-(iv),D-(iii)
D. A-(iii),B-(ii),C-(iv),D-(i)

Answer

To solve the matching question, we will analyze each item in Column I and find the corresponding item in Column II.

### Step-by-Step Solution:

1. **Fast Muscle Fibers**:
- Fast muscle fibers are known for their ability to contract quickly and powerfully. They contain a large amount of myoglobin, which helps in oxygen storage and is crucial for aerobic respiration.
- **Match**: Fast muscle fibers → Myoglobin (i).

2. **Slow Muscle Fibers**:
- Slow muscle fibers are characterized by their endurance and ability to sustain prolonged activity. They primarily rely on aerobic metabolism and produce lactic acid during anaerobic conditions.
- **Match**: Slow muscle fibers → Lactic acid (ii).

3. **Actin Filament**:
- Actin filaments are one of the main components of the muscle fibers and are associated with the light band in the sarcomere structure, which is referred to as the I-band.
- **Match**: Actin filament → I-band (iv).

4. **Sarcomere**:
- The sarcomere is the basic contractile unit of muscle fibers, responsible for muscle contraction. It is made up of actin and myosin filaments.
- **Match**: Sarcomere → Contractile unit (iii).

### Summary of Matches:
- Fast muscle fibers → Myoglobin (i)
- Slow muscle fibers → Lactic acid (ii)
- Actin filament → I-band (iv)
- Sarcomere → Contractile unit (iii)

### Final Answer:
Based on the matches, the correct option is:
- A is i (1)
- B is ii (2)
- C is iv (4)
- D is iii (3)

Thus, the correct option is **Option 1**.