Step 1: Understanding Oxygen Requirements.
- Group A:
- P: Micrococcus luteus is an obligate aerobe, meaning it requires oxygen to grow.
- Q: Spirillum volutans is a microaerophilic organism, which requires a low oxygen concentration.
- R: Methanobacterium formicicum is an obligate anaerobe, meaning it thrives in the absence of oxygen.
Step 2: Group B Oxygen Requirements.
- Group B:
- i: Obligate anaerobe
- ii: Facultative aerobe
- iii: Obligate aerobe
- iv: Microaerophilic
Step 3: Conclusion.
Thus, the correct matching is:
- P: iii (obligate aerobe)
- Q: ii (facultative aerobe)
- R: i (obligate anaerobe)
Hence, the correct answer is (D).