I'm gonna say D is the answer.
Answer:
Because the earth's axis is tilted. It is all about the tilt of the Earth axis.
Explanation:
Electrocardiograph (EKG or ECG) technicians operate equipment that measures, monitors, and graphically traces the electrical activity of the heart. Physicians use the graph (electrocardiogram/EKG/ECG) to diagnose and monitor patients' heart problems.
The correct answer to my knowledge would be 45.
Assuming that the 10 soils are each represented by A, B, C, D, E, F, G, H, I, J.
A can combine with 9 others as: AB AC AD AE A F AG AH AI AJ
B can combine as: BC BD BE BF BG BH BI BJ
C as: CD CE CF CG CH CI CJ
D as: DE DF DG DH DI DJ
E as: EF EG EH EI EJ
F as: FG FH FI FJ
G as: GH GI GJ
H as: HI HJ
I as: IJ
Once you add all the combinations together, you get 45.
Hoping this helped you!
