Answer:D
Explanation: Because it has the least amount of density in it. All the others are heavier, meaning they will sink. Just like if you drop a rock water and a feather, the feather will float.
Density def:
Density, mass of a unit volume of a material substance. ... Density offers a convenient means of obtaining the mass of a body from its volume or vice versa; the mass is equal to the volume multiplied by the density (M = Vd), while the volume is equal to the mass divided by the density (V = M/d).
it has an alternating chemical<span> phosphate and </span>sugar<span> backbone, making the 'sides' of the ladder. (Deoxyribose is the name of the </span>sugar<span> found in the backbone of DNA.) In between the two sides of this </span>sugar<span>-phosphate backbone are four nitrogenous bases: adenine (A), thymine (T), </span>cytosine<span> (C), and guanine (G).</span>
Thermodynamics is the correct answer.