The correct statement is that viruses are not living, although this concept is widely debated. In truth, viruses are neither living nor non living, they have not been classified properly as of yet. Viruses do NOT have organelles and they can NOT produce their own energy thus they rely on other cells to provide energy and to reproduce and spread the virus for them to other cells. (I'm fascinated by viruses, sorry i rambled!)
D. Mass consumption
is the answer
If A. is caves then A would be your answer.
<span>W</span><span>ith growing worldwide interest in the oil and gas</span>
r<span>eserves of the Caspian region, the ecological prob-</span>lems of the area are also receiving increased attention.Due to its position in the far southeast of Europe, littleinformation about the region was available in the Westuntil recently, and it was not until a few years ago thatthe public became aware of the potential disasterthreatening the unique ecosystem of the Caspian Seaand its immediate surroundings (Dumont 1995). Stone(2002) described most of the acute problems in thisarea: reduction of the river run-off reaching theCaspian Sea caused by damming the main tributary,the Volga river; the unstable water level; the varioussources of pollution; the over-utilisation of its livingr<span>esources (in particular the sturgeon species); and,</span>finally, the threat to the entire system posed by a newinvader, the ctenophore <span>Mnemiopsis leidyi<span>.</span></span>