A reaction produced a mixture of the following two compounds, which were separated. How can we determine which diastereomer is in which separated sample using only the ¹H NMR data?

• A. Structure I is expected to have more complex splitting patterns in its spectrum.
• B. Structure II is expected to have more complex splitting patterns in its spectrum.
• C. Structure I is expected to have more downfield signals in its spectrum.
• D. Structure II is expected to have more downfield signals in its spectrum.