The following are some major events in the early history of life.
P. First heterotrophic prokaryotes
Q. First genes
R. First eukaryotes
S. First autotrophic prokaryotes
T. First animals
Which option below places these events in the correct order?

Options

A. PQRST
B. QSPTR
C. QPSRT
D. QSPRT

Answer

To arrange the major events in the early history of life in the correct order, we will analyze each event step by step.

### Step-by-Step Solution:

1. **Identify the First Event: First Genes (Q)**
- The very first event in the history of life is the emergence of the first genes. This is believed to have occurred in the form of RNA and DNA, which are essential for the development of life.

2. **Identify the Second Event: First Heterotrophic Prokaryotes (P)**
- After the formation of the first genes, the next significant event was the appearance of the first heterotrophic prokaryotes. These organisms obtained their energy by consuming organic molecules from their environment.

3. **Identify the Third Event: First Autotrophic Prokaryotes (S)**
- Following the heterotrophic prokaryotes, the first autotrophic prokaryotes emerged. These organisms were capable of producing their own food through processes like photosynthesis, especially after the depletion of available organic molecules.

4. **Identify the Fourth Event: First Eukaryotes (R)**
- The next major development was the evolution of the first eukaryotes. These cells are more complex than prokaryotes and contain a nucleus and organelles.

5. **Identify the Fifth Event: First Animals (T)**
- Finally, the first animals appeared. This event marks the emergence of multicellular organisms that are more complex and capable of various forms of life.

### Correct Order:
The correct order of events is:
1. First Genes (Q)
2. First Heterotrophic Prokaryotes (P)
3. First Autotrophic Prokaryotes (S)
4. First Eukaryotes (R)
5. First Animals (T)

Thus, the correct sequence is QPSRT.

### Conclusion:
The correct option that represents this order is option 3 (QPSRT).