Which of the following is true about homogeneous mixtures that are made by mixing two or more pure substances?​​​​​​

a. They cannot be separated physically as they are formed by combining two or more pure substances.
b. They can never be solids as they are solutions and solutions are a mixture of two or more liquids in their pure form.
c. They can be separated physically as they are physical mixtures of two or more pure substances.
d. They can be separated chemically as they are physical mixtures of two or more pure substances.