B. The sika deer out competed the white-tailed deer in consuming flowering plants and shrubs.
I think the correct answer would be the third option. Organisms that help break down dead organic material so it can be recycled into a usable form for other organisms are called decomposers and this would include some of the bacteria. Also, there is a number of bacteria that are capable of breaking down some of the harmful products like in recent studies there are bacteria that could dechlorinate the toxic PCB substance. Some bacteria, as well, lives in the human intestines which aids in the breaking down of the food into useful molecules. The third option is partially true since there are some bacteria like the cyanobacteria which produces oxygen but it does not contribute largely to the oxygen present in the atmosphere.
The correct answer is - phototrophs.
Some of the autotrophs are able to convert the electromagnetic energy from the sunlight into chemical energy in the form of reduced carbon (C). The autotrophs that are able to perform this are called phototrophs. The green plants and the algae are the most prominent members of the phototroph autotrophs.
In essence, the autotrophs are producers, meaning that they are able to produce their own food. The phototrophs are the part of the autotrophs that are able to use the sunlight to produce small amounts of ATP as well as the energy carrier NADHP. By producing the ATP and the NADHP the phototrophs manage to produce glucose, or rather sugars, which are actually their food.