Final answer:
Josquin des Prez used melodic and rhythmic variations to contrast the final two lines of 'O mater Dei, memento mei' in his composition. Dynamic and harmonic contrasts may not specifically describe the contrasts in these lines.
Step-by-step explanation:
When discussing how Josquin des Prez contrasts the final two lines of the text 'O mater Dei, memento mei', it is important to consider the techniques used in Renaissance music. Josquin often employed melodic variation and rhythmic variation to provide contrast and emphasize certain parts of the text. In contrast, while dynamic and harmonic contrasts are possible musical techniques, they might not necessarily be explicitly used to differentiate the final two lines.
The rich tradition of polyphony during the Renaissance, characterized by independent voices and concurrent melodies, often led to these variations naturally occurring as part of the evolving musical structure.
Therefore, options (a) melodic variation and (b) rhythmic variation describe how Josquin creates contrasts in the final two lines of 'O mater Dei, memento mei'. Options (c) dynamic contrast and (d) harmonic contrast may not specifically describe the contrasts in the final two lines, although they are still important musical elements in Renaissance compositions.