The answer for your question is Monitor
The correct answer is: A. How does changing the amount of water affect the growth of corn?
While options B, C & D are not impossible to test, option A is the only question that can be tested using quantitative methods, such as statistical analysis. The question in option A states: "How does changing the amount of water affect the growth of corn?". This question is easily testable using scientific investigation, because controlled or measured amounts of water can be added to corn, and the consequent growth rate of corn can be easily measured and recorded. However, the questions in options B, C & D cannot be precisely measured using quantitative tools, since they aim to measure qualitative (subjective) factors, such as: ethics, happiness and disappointment.
The polarity of water allows it to dissociate ionic and other polar compounds, thus allowing many important chemical reactions to occur. Those reactions are called aqueous reactions. Most of the reactions that sustain life are aqueous with water acting as the "universal solvent".
T cell receptor, Cytotoxic T Cell, CD4, Antigen, Bacterium,
B – cell, Cell mediated response, Class II MHC, Cytokines, and Humoral Response
are the components for the activation of a helper t cell by a dendritic cell.
