What is the primary significance of the 'Parable of the Sower' (Matthew 13:1-23), beyond simply illustrating different responses to the Gospel?

A It primarily emphasizes the importance of eloquent preaching to ensure the Gospel is well-received. B It highlights God's indiscriminate distribution of grace, regardless of the soil's condition. C It reveals that the effectiveness of the Gospel message depends solely on the inherent receptivity of the individual's heart, independent of external factors. D It underscores the reality that not all who hear the message of the Kingdom will ultimately bear fruit, and the reasons why.