Chemosynthetic bacteria :
(a) oxidise inorganic compounds to acquire energy
(b) are autotrophic
(c) use the sun rays to acquire energy
(d) both (a) and (b)

Options

A. oxidise inorganic compounds to acquire energy
B. are autotrophic
C. use the sun rays to acquire energy
D. both (a) and (b)

Explanation

To solve the question about chemosynthetic bacteria, we need to analyze each option provided:

1. **Understanding Chemosynthetic Bacteria**:
- Chemosynthetic bacteria are a unique group of bacteria that obtain energy through the oxidation of inorganic compounds. This process is essential for their survival and metabolic functions.

2. **Analyzing Each Option**:
- **Option (a)**: "oxidise inorganic compounds to acquire energy"
- This statement is true. Chemosynthetic bacteria indeed oxidize inorganic compounds (like hydrogen sulfide, ammonia, etc.) to obtain energy.

- **Option (b)**: "are autotrophic"
- This statement is also true. Chemosynthetic bacteria are considered autotrophs because they can produce their own food using inorganic substances and do not rely on organic compounds.

- **Option (c)**: "use the sun rays to acquire energy"
- This statement is false. Chemosynthetic bacteria do not use sunlight for energy; instead, they rely on chemical processes involving inorganic compounds.

- **Option (d)**: "both (a) and (b)"
- Since both statements (a) and (b) are true, this option is also correct.

3. **Conclusion**:
- The correct answer is **(d) both (a) and (b)**, as chemosynthetic bacteria oxidize inorganic compounds to acquire energy and are classified as autotrophic organisms.