In the experimental process, the scientists made all measurements for material A before beginning to take measurements for material B. Was this a valid approach?

A.) No; in order to compare materials, they must be analyzed at the same time.
B.) Yes; materials can be tested in any order as long as all measurements are recorded carefully.
C.) Yes; testing material B before testing material A, however, would have invalidated the results.
D.) No; the results of the first test could have influenced the results of the second test.