I think the correct answer choice is c
Answer:
Explanation:
Geologists record the seismic waves and study how they travel through Earth. The speed of these seismic waves and the paths they take reveal how the planet is put together. Using data from seismic waves, geologists have learned that Earth's interior is made up of several layers.
Id say this is more of a biology question or even a psychology question , well its not a question at all but the endocrine system is a collection of glands that secrete hormones direct to the blood system (circulatory system) to be sent to the desired / target organ , an example of a gland could be the pituitary gland (located towards rear of brain)
