Ibn Battuta's description of the 'Coconut' as "Nut like a man's head" is a vivid and comparative way to convey the size and shape of coconuts. Here's the reason for this description:

Comparative Description: In his travel accounts, Ibn Battuta often used familiar and relatable comparisons to help his readers understand the characteristics of the places, people, and things he encountered. Describing the coconut as "Nut like a man's head" gives the reader a visual reference, comparing the size and shape of the coconut to something universally recognizable.

Visual Aid: This description assists in creating a mental image for the reader, helping them understand the size and appearance of the coconut, which may have been unfamiliar to some of Ibn Battuta's audience.

Cultural Perspective: Ibn Battuta's writings are valuable historical records that offer insights into the cultural and natural aspects of the regions he visited. His descriptions, including those of natural resources like coconuts, provide readers with a glimpse of how these resources were perceived and used in different parts of the world during his travels.

So, the correct option is [2].