The pH scale is a logarithmic one, meaning that each pH unit has 10 times as many hydrogen ions as the unit above it. So, at pH 4, there are 10 times more hydrogen ions than at pH 5 and 100 times more hydrogen ions than at pH 6.
remember skeletal is voluntary; smooth and cardiac are involuntary
The correct answer of the given question above would be the third option. The statement that depends on the absolute dating of events is this: The oldest Earth rocks are 3.9 billion years old. Absolute dating is the method of determining the specific date of an archaeological or paleontological artifact. In contrast, relative dating is just the determining of the relative order of events and not necessarily the estimated age of the artifact.
The answer to the question is d