I also believe the answer is A.
I'd say zoology.
Zoology is the study of animals, generally speaking, and since birds are animals, the study of these fall into the field zoology. The study of birds though, is called ornithology.
Hope it helped,
BioTeacher101
Answer:
1) Organisms in this level are either unicellular or colonial (Cellular level).
2) Organisms that live in a group called a colony (Colonial).
3) The work being divided up into specialized tasks (Division of labor).
4) A very long, contracting cell (Fiber).
5) A group of tissues working together as a unit (Organ).
6) A degree of organism complexity. Organisms at this level have their cells arranged into organs (Organ level).
7) The highest level of complexity of a living thing (Organism level).
8) The limiting of the function of a cell to a specific function muscle (Specialization).
9) A group of organs working together for a common purpose (System).
10) Organisms at this level have their cells arranged into systems (System level).
11) Cells working together to perform a particular task division of labor (Tissue).
12) Organisms at this level have their cells arranged into tissues (Tissue level).
Answer: the relative differences in arrival times of the S and P seismic waves at several recording stations tell scientists about the different speeds those waves were traveling at, which in turn gives information about the density of the material the layer is made of, and how thick the layer is in several directions.
Explanation:Earth's layers