The correct answer should be (d) The Krebs cycle
After Glycolysis, the Krebs cycle begins in the matrix of the mitochondrion.
Several species of warblers can live in the same spruce tree only because they occupy different nitches within the tree. So option "c" is the correct option as far as the given question is concerned. These birds may not be of the same species but they do have some similarities like they are very vocal and can be rarely seen but definitely heard. All species of warblers are insectivorous and also very small. As they are small so identifying them can be very difficult for a person. These birds are mostly dull greenish or brownish in color.
A is the active site and C is the enzyme
In physical science there are two types of "isolated systems"
1. Being a Physical System in which it is so far removed from other systems that it does not react with any of them.
2. Being a Thermodynamic System in which it is enclosed by rigid immovable walls of which neither mass nor energy can flow through.
I believe in this case although not stated that it would refer to a Thermodynamic System which would leave you with the only plausible answer as ENERGY AND MATTER CANNOT ENTER OR LEAVE.
None of the other answers make sense. Even if it were referring to Physical. Physical does not react with anything at all. An as you can see Thermodynamic does not allow for anything to pass through or leave.
