The correct answer is: "Noting the color of a solution as it is heated."
To understand this answer, let's first clarify what qualitative data is: Qualitative data is data that is descriptive, describes the attributes of something and it cannot be represented numerically. From the options listed the question, noting the color of a solution as it is heated, is the only statement that describes qualitative data. The color of a solution is an attribute of the solution that cannot be represented quantitatively-using numbers. On the other hand, the other options listed describe quantitative data, which are all measurable and can be represented numerically.
