Task: Question Generation
Input (English): Once the meditator achieves a strong and powerful concentration (jhāna, Sanskrit ध्यान dhyāna), his mind is ready to penetrate and gain insight (vipassanā) into the ultimate nature of reality, eventually obtaining release from all suffering. The cultivation of mindfulness is essential to mental concentration, which is needed to achieve insight.
Output (English): Mindfulness is essential to concentration, which is neede to achieve what?