Answer: Option (a) is correct
Explanation:
Biological anthropologist are the people who study behaviors and biological characteristic of humans residues,ancient resources etc.
According to the question, biological anthropologist study the mechanism of environment adaption, evolution, history of development and existence, variation and origin of human beings.
Other options are incorrect because genes effect, makeup of biology and environment impact are not the factors that defines humans as per concept of anthropologist.Thus, the correct option is option(a)
Agriculture is the most appropriate answer.
'Vassals were the lowest class in the newly established government system's hierarchy.
<h3>
What is hierarchy?</h3>
A hierarchy is an arrangement of items (objects, names, values, categories, and so on). Hierarchy is a key concept in many disciplines, including architecture, philosophy, design, mathematics, computer science, organizational theory, systems theory, systematic biology, and social sciences.
A hierarchy can connect entities directly or indirectly, and it can connect entities vertically or diagonally. In a hierarchical system, the only direct links are to one's immediate superior or to one of one's subordinates, though a largely hierarchical system can also incorporate alternative hierarchies. Hierarchical links can extend "vertically" upwards or downwards by following a path with multiple links in the same direction.
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