You have developed a promising anti-cancer agent, but it has poor solubility in water. which of the following changes should improve water solubility?
a.
adding a methyl group
b.
adding a hydroxyl group
c.
adding a carboxyl group
d.
increasing the size of the drug
e.
adding a benzene ring

The correct options is B.

Explanation:

Adding a hydroxyl group to the anti-cancer agent will increase its ability to dissolve in water. This is because hydroxyl (OH) group is a functional group that contain oxygen. The oxygen atom present in OH group readily form chemical bond with the hydrogen atoms of water; this increase the solubility of the substance in water.

Another functional group that behave in the same way with OH group is the carbonlyl group, this functional group also has the ability to increase solubility of substances in water. Carbohydrates generally are soluble in water because their structures are made up of both hydroxyl and carbonyl groups.  

the cell theory states that all living things including animals, as well as plants, are made of cells.

the answer to your question is b