The correct answer is option 'A', Aristotle, who is known as the father of biology.

Aristotle (384-322 BC) was an ancient Greek philosopher and scientist who made significant contributions to many fields, including biology. He is considered the founder of the biological sciences because of his extensive studies and observations of the natural world.

Aristotle's contributions to biology can be divided into several key areas:

1. Classification of Organisms:
Aristotle was the first to develop a systematic method for classifying and categorizing living organisms. He grouped animals into different categories based on their characteristics, such as their habitat, body structure, and reproductive methods. This classification system laid the foundation for modern taxonomy.

2. Study of Anatomy and Physiology:
Aristotle conducted detailed anatomical studies of various animals, including dissecting them to understand their internal structures and functions. He observed and described the organs, tissues, and systems of different organisms, providing valuable insights into their physiology.

3. Observations of Animal Behavior:
Aristotle closely observed and documented the behavior of different animals, including their mating rituals, social structures, and habits. He recognized that behavior is an essential aspect of an organism's biology and can provide insights into its survival strategies and interactions with the environment.

4. Study of Reproduction:
Aristotle studied various aspects of reproduction in animals, including the development of embryos and the processes of fertilization and gestation. He proposed the theory of epigenesis, which suggests that organisms develop from an undifferentiated form into their specific structures over time.

5. Contributions to Botany:
Although Aristotle is primarily known for his contributions to zoology, he also made significant observations and classifications in the field of botany. He studied plant growth, reproduction, and the diversity of plant species, contributing to our understanding of plant biology.

Overall, Aristotle's systematic approach to studying and understanding the natural world laid the foundations for modern biology. His observations, classifications, and theories formed the basis for later scientific advancements in the field. Therefore, he is widely regarded as the father of biology.