Definitely #2 is the answer
Limiting factors
for example: amount of food, water, shelter, predators, etc
The planet closest to the sun is mercury and this is because the order of the planets in the solar system, starting nearest the sun and working outward is the following: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and then the possible Planet Nine. If you insist on including Pluto, it would come after Neptune on the list.
The seeds she planted in the mud grew quicker because the mud is holding nutrition for the corn. The soil is a good guess to make, but the mud is more dense and moist. The water wouldn't have had more nutrients than the mud, just because the mud holds breakdown matter and other things from other plants.
It reproduce by a process call Binary Fission
