Option B- They play a minor role in biological and geo-chemical cycles is the right answer.
Marine microbes are tiny, single-celled organisms that live in the ocean. They play a major role in biological and geo-chemical cycles.
Both elements are coinage metals and they are godd conductor of electricity and heat.
Hope I helped !
If you believe in the Bible, there is a story at the beginning in Genesis where God sent a huge ran causing flood waters to cover the earth,