[Solved] Which of these is NOT one of the 4 Vs of Big Data? A)Volume B)Velocity C)Variety D)Viscosity Microorganisms: Very small, often single-celled organisms that can be bacteria, fungi, viruses, or protozoa, not visible to the naked eye. Iron Formation: A sedimentary rock consisting of alternating layers of iron-rich minerals and silica or carbonate, typically formed in Precambrian seas. Seawater: The saltwater that makes up the oceans and seas, covering more than 70% of the Earth's surface, containing various salts and life forms. Silica-rich Organisms: Organisms that produce silica (silicon dioxide) as part of their structure, such as diatoms and certain sponges.