In a Study Examining Brain Differences Between Practitioners of Meditation

In a study examining brain differences between practitioners of meditation and those who never meditated, MRI scans showed that:

A) cortical thickness was negatively correlated with meditation experience.
B) several cortical areas were thinner in the meditators' brains than in the nonmeditators' brains.
C) the meditators had more gray matter than the nonmeditators in regions associated with attention, emotion, and sensory processing.
D) meditators and nonmeditators have identical brains.