Answer:
The correct answer is C. gases.
Chemical reaction is the process by which one or more substances are converted into different substance or substances.
The substances which undergo chemical reaction are called as reactants while the substances which are produced by the reaction are called as products. During chemical reaction, chemical bonds of substrates undergo breaking and formation process to form an entire new product which may have same or different physical and chemical properties as compared to substrates.
Energy is either used or released during the chemical reaction. When the energy is used, it is termed as endothermic reaction but when the energy is produced by the reaction, it is termed as exothermic reaction.
Lastly, gases may or may not participate in a chemical reaction.
The most accurate classification of the common forms of coronary artery disease and hypertension is that they are complex disorders which result from gene-environment interactions. For example, almost 60% of CAD cases are found in South East Asia, that too when their population if just 20% of the total world's population. This is due to the environmental interactions with the genetic disposition of the people of this region.
It think its mitosis because the get denser then they separate so they can make a new cell. Hope this helps