Consider the following statements: Statement I: Studies indicate that carbon dioxide emissions from cement industry account for more than 5% of global carbon emissions. Statement II: Silica-bearing clay is mixed with limestone while manufacturing cement. Statement III: Limestone is converted into lime during clinker production for cement manufacturing. Which one of the following is correct in respect of the above statements?

Statement I: Correct. Cement industry is responsible for roughly 7–8% of global CO2 emissions, so "more than 5%" is true.

Statement II: Correct. Cement is made by heating a raw mix mainly of limestone and silica-bearing materials such as clay/shale; this explains emissions partly because fuel is burned in the kiln.

Statement III: Correct. During clinker production, limestone (CaCO3) is calcined to lime (CaO), releasing CO2 directly; this is a major reason for cement-sector emissions.

Option check: Both Statements II and III are correct, and both explain Statement I—II through energy-intensive kiln heating and III through process emissions from calcination. Hence (a).