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. `PrarrQrarrSrarrRrarrT`
B. `QrarrSrarrPrarrTrarrR`
C. `QrarrPrarrSrarrRrarrrT`
D. `QrarrSrarrPrarrRrarrT`

Answer

To determine the correct order of the major events in the early history of life, we need to analyze the given events step by step:

1. **First Genes (Q)**: The formation of genetic material is essential for the origin of life. Before any living organism can exist, there must be a mechanism to store and transmit genetic information. Therefore, the first event is the emergence of the first genes.

2. **First Autotrophic Prokaryotes (S)**: After the formation of genes, the next step involves the development of simple life forms. Autotrophic prokaryotes, which can produce their own food through processes like photosynthesis, would have emerged next. They are crucial as they serve as primary producers in the ecosystem.

3. **First Heterotrophic Prokaryotes (P)**: Following the autotrophs, heterotrophic prokaryotes would arise. These organisms depend on autotrophs for their nutrition, making them the consumers in the ecosystem.

4. **First Eukaryotes (R)**: Once prokaryotic life forms were established, more complex cells known as eukaryotes would develop. Eukaryotic cells have membrane-bound organelles and a defined nucleus, representing a significant evolutionary advancement.

5. **First Animals (T)**: Finally, after the establishment of eukaryotic cells, multicellular organisms, including animals, would evolve. This marks the emergence of complex life forms.

Thus, the correct order of events is:
1. First Genes (Q)
2. First Autotrophic Prokaryotes (S)
3. First Heterotrophic Prokaryotes (P)
4. First Eukaryotes (R)
5. First Animals (T)

### Final Order:
Q → S → P → R → T