Ved Vyasa is traditionally believed to have dictated the text of the Mahabharata to Lord Ganesha for several reasons:

Divine Assistance: Lord Ganesha is revered as the god of wisdom, intellect, and knowledge. His association with writing and wisdom made him the ideal deity to assist in the task of transcribing the vast and complex epic.

Vastness and Complexity: The Mahabharata is one of the longest and most intricate epics in the world, with numerous characters, stories, and teachings. Given its immense scope, Ved Vyasa sought divine assistance to ensure that nothing was missed or distorted during the recitation.

Error-Free Transmission: Lord Ganesha is believed to have the ability to write without pause and understand the nuances of the text. This was important to ensure that the Mahabharata was transcribed accurately and completely.

Spiritual Significance: The act of Lord Ganesha writing down the Mahabharata is symbolic of the divine and human collaboration in preserving and passing down ancient wisdom and knowledge.

So, the correct option is [3].