If they are trying to convert any measurements or just measure out the chemicals, it wouldn't be very familiar to them so they could make a mistake that can result of too much or too little of the chemicals, which can make the chemicals react differently.
The answer is A) food web. B is not actually a thing, and C and D are very different vocab words.
binary fission?
In binary fission, the parent is split into two daughter cells, each genetically identical while receiving a copy of DNA