Which Claim Has a Scientific Basis and Why

Which claim has a scientific basis and why?

A) Animals can understand the meanings of words, because it has been shown that they respond to specific oral commands.
B) Psychological factors improve some health conditions, because people taking pills containing no medication have shown health improvements.
C) A huge aquatic creature inhabits the extremely deep lake in Loch Ness, Scotland, because parts of it have been observed by many people over many decades.
D) Life must exist on other planets, because there are so many other planets that it would be impossible for all of them to be devoid of life.
E) Extrasensory perception has been claimed to be a real phenomenon, because so many people have experiences that have no other explanation.