Answer: All the statement are true except Option C. It is usually a good idea to measure a variable at the lowest level of measurement
Explanation: when measuring variables, we are required to measure with a scale which will help us to classify the variable. Variables are samples of a research to be studied, we measure this variables to be able to classify them. For instance if we want to know how people feel about an event, we can measure them using "very sad", "sad", "happy", and "very happy". If you choose only the lowest measurement which is very sad, we have just categorized every one to be very sad, and this will affect the accuracy of our result.