On shaking acetic acid with water

Acetic acid ($CH_3COOH$), as mentioned in Table 4.1 of the text, is a polar organic compound that is completely miscible with water. When mixed, the molecules of acetic acid distribute uniformly throughout the water, resulting in a single-phase homogeneous mixture (a true solution). Option A is incorrect because colloids involve larger particle sizes ($1$ to $1000$ nm) which acetic acid does not form in water. Option B is incorrect because suspensions involve insoluble particles that settle over time. Option D is incorrect because a heterogeneous mixture would show distinct layers or boundaries, which does not happen with acetic acid and water.