The four level pyramid model revolves around the. Who use the system

Explanation: The pyramid model of four level in an organization is based on and is depends on the various levels of the hierarchy systems or management in the organization. These four level is of different types of the Information System in the organization.

Explanation:

6.4 cm (max) - 25 cm (min)

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.