Bunuel wrote:
A study was designed to establish what effect, if any, the long-term operation of offshore oil rigs had on animal life on the bottom of the sea. The study compared the sea-bottom communities near rigs with those located in control sites several miles from any rig and found no significant differences. The researchers concluded that oil rigs had no adverse effect on sea-bottom animals.
Which one of the following, if true, most seriously weakens the researcher’ conclusion?
Hi
burh4niPlease find my explanation below:
Conclusion : Oil rigs had no adverse effect on sea-bottom animals
Pre-Thinking :
1) Maybe we aren't analyzing the long-term effect of these rigs on the sea-bottom animals.
2) As we are just conducting the tests near the rigs vs control sites, there might be a butterfly effect. As conclusion is generic to all the sea-bottom animals. These rigs should not affect sea-bottom animals anywhere else.
(A) Commercially important fish depend on sea-bottom animals for much of their food, so a drop in catches of these fish would be evidence of damage to sea-bottom communities.
OFS, Irrelavant to the conclusion.(B) The discharge of oil from offshore oil rigs typically occurs at the surface of the water, and currents often carry the oil considerable distances before it settles on the ocean floor.
Yeah in line with our pre-thinking. This could affect the life of sea-bottom animals in those places.(C) Contamination of the ocean floor from
sewage and industrial effluent does not result in the destruction of all sea-bottom animals but instead reduces species diversity as well as density of animal life.
Trap, This contamination is not caused by oil rigs. We are only concerned about Oil rigs contamination.(This is a perfect trap)(D) Only part of any oil discharged into the ocean reaches the ocean floor: some oil evaporates, and some remains in the water as suspended drops.
Strenghtens as there might not be much contamination.(E) Where the ocean floor consists of soft sediment, contaminating oil persists much longer than where the ocean floor is rocky.
OFS, Irrelavent with is argument.If you find this post helpful, Please give me kudos and help me to reach the next level.Thanks