Alkanes are linear, or branching, compounds that are made of varying numbers of carbon atoms that are all saturated with hydrogen atoms. The formula for an alkane is CnH(2n+2). This means that the number of hydrogen atoms equals twice the number of carbon atoms, plus two. Methane is the simplest hydrocarbon possible.
When the liquid metal that creates the outer core of the earth passes through a magnetic field, it begins to carry the electric current through the liquid. This current makes its own, much stronger magnetic field.
Answer is A.
Archaea requires neither sunlight for photosynthesis as do plants, nor oxygen. Archaea absorbs CO2, N2, or H2S and gives off methane gas as a waste product the same way humans breathe in oxygen and breathe out carbon dioxide. An example is chemosynthetic bacteria by sea drifts. They use chemical energy to produce vital processes to live.