What is the MOST important reason to control the condition of an experiment?

Ineed to know why d is the correct answer asap

Actinobacteria sp. are fermenting organisms (which do you use oxygen to breathe) referred to as chemoorganohetereotrophs this means they break down organic material and convert it to inorganic material. which part of the carbon cycle does this describe

Onsider the paragraph above. what is one chemical property of water? a) water is a polar molecule. b) water is the universal solvent. c) water reacts with group 1 metals. d) water has a high specific heat capacity.