First life consisted of

Options

A. Provirus
B. Virus
C. Bacteria
D. Protovirus

Explanation

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the composition of the first life forms on Earth. We need to identify which option correctly represents this.

2. **Reviewing Historical Theories**: According to the transcript, Ayrton Taylor proposed that the first life forms were primitive viruses, which he termed "protoviruses." This suggests that the earliest life consisted of these simple viral entities.

3. **Analyzing Options**:
- **Provirus**: This term refers to a viral gene that has been incorporated into a host genome. Since proviruses are derived from existing viruses and not the first life forms, this option is incorrect.
- **Viruses**: While viruses are related to protoviruses, they are not considered the first life forms. Thus, this option is also incorrect.
- **Bacteria**: Bacteria are often considered some of the earliest life forms, but according to the information provided, protoviruses predate them.

4. **Conclusion**: Based on the information provided, the first life consisted of protoviruses. Therefore, the correct answer is **protovirus**.

### Final Answer:
The first life consisted of **protovirus**.

---