The answer you are looking for is the second option, "Matter can be divided into two groups: pure substances and mixtures."
A pure substance can describe a pure element or chemically bonded elements. A pure substance cannot be broken down into further substances. An example of these would be Fe (iron) or O2 (oxygen).
A mixture is a structure made from physically combining different non-bonded substances. An example of a mixture is blood.
Both pure substances and mixtures are types of matter.