When part of a population of a species gets separated from the remainder, it is termed as geographical isolation. It may evolve different characteristics due to genetic change over a period of time. If geographical barriers are removed by the humans, members of two populations will be unable to mate successfully each other and as a result new species will emerge. The formation of new species is termed as speciation. Speciation due to geographical isolation is called allopatric speciation
The organism that grows on the body of another organism and derives nutrients from it is known as a parasite. The organism that obtains nutrients from the dead or decaying organic matter is called saprotroph.
It is mostly like "B". A new area of science promotes experimentation from a different point of view because everything else is explains why the development of the new area of science which could lead to change in a particular theory but they aren't quite the "best" one
