The speed of seismic waves varies as they travel through Earth because
A. Temperature varies within the Earth
B. Density of rocks varies within the Earth
C. The composition of rocks varies within the Earth
D. All of the above
Help pleasee

Here's link to the

tinyurl.com/wpazsebu

I think its C but you can choose B&C

Explanation:

A (and D) is not the answer because natural disaster dosent matter with temperatures.

dna is made up of six smaller molecules -- a five carbon sugar called deoxyribose, a phosphate molecule and four different nitrogenous bases (adenine, thymine, cytosine and guanine).