The correct option is C Both (a) and (b)
Homogeneous Mixtures:
Mixtures in which single phase is visible. It has uniform composition and properties throughout.
Ink in water and CO2 (g) in H2O (l) are examples of homogenous solutions.
Carbon dioxide reacts with water to form carbonic acid.
Heterogeneous mixtures:
Mixtures that contain physically distinct parts and have non-uniform compositions.
Sand in water, Oil in water are examples of heterogeneous mixtures.
Hence, the correct answer is option (c).