What is the likely source of methane in mars atmosphere?

 UV can also generate methane from organic materials in the Martian surface. Other possible sources for methane on Mars include reactions between water and olivine, and, hypothetically, microbes. Methane generated underground in the distant or recent past might be stored within lattice-structured methane hydrates called clathrates, and released by the clathrates at a later time, so that methane being released to the atmosphere today might have formed in the past.

The best answer is (a) which is universal law is in effect at all times. it is constantly at play in everything we do and governs our lives. it is also important to note that universal law applies to not only everything on earth, but everything in the universe as well, which is another reason why it is in effect at all times.

Answer (d) valerie rides her bike south at 8 kilometers per hour///owen jogs south at 8 kilometers per hour ;