What type of data is recorded by the electrocardiogram? A. the amount of oxygen in the blood B. the sound of the heart beating C. the force from the heart beating D. the electrical activity of the heart

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.