The answer would be :People, animals, water & the wind.
The reason as to why these would be the answer is because the wind disperses seeds by blowing them through the air to different locations. The water washes the seed away to a location away from the parent. Animals disperse seeds, when they leave behind their waste and the seeds are in the waste. Lastly people disperse seeds in many ways, but one of them would be like throwing them into the grass, and ir planting them.
