The novelist's prose was often praised for its ______ quality, a style that managed to be both deeply ______ and remarkably accessible to a wide readership.

✓ Correct Answer: Option C

The sentence describes a prose style that is 'deeply' something and 'remarkably accessible.' 'Profound' (deep, insightful) fits 'deeply,' and 'lucid' (clear, easy to understand) fits 'accessible,' creating a positive and balanced description.