Hint: Hydrochory means dispersal of seeds and fruits by water. This means of seed dispersal is generally used by aquatic plants and some terrestrial plants which grow near the water source. This means of dispersal is applied to the seeds and fruit which are waterproof and can float on water.
To solve this question, we must know about the structure of coconut fruit.
Coconut tree is the member of the palm family. It is the only living species of genus Cocos. The fruit of coconut is called a drupe.
The fruit of coconut has three layers.
Exocarp- It is the outermost layer of the fruit which is coated with wax.
Mesocarp- It is composed of fibres. The fibrous mesocarp is used for making ropes and bags.
Endocarp- It is stony in nature and protects the flesh of coconut which is edible.
For hydrochory, the fruit should be fibrous and waterproof. The fibrous mesocarp helps it to float in water and the stony endocarp protects the seed from water. Hence coconut is easily dispersed by water.
Hence, the correct answer is option (D)
Note: The function of endocarp is to protect the seed and also help in seed dispersal. It also plays a vital role in sustaining and communicating with the developing seeds. The endosperm contains a large quantity of liquid which is edible.