Question

which of the following limits the biodiversity of grasslands?
grazing animals
pesticides and fertilizers
farming a single variation of a crop
loss of topsoil

Explanation:

Grazing animals can over - graze, but they are a natural part of grasslands and can sometimes increase biodiversity in a balanced state. Pesticides and fertilizers can have negative impacts, but their direct effect on grassland biodiversity is not as fundamental as some other factors. Farming a single crop is more relevant to agricultural fields rather than natural grasslands. Loss of topsoil is a major issue as it affects the ability of plants to grow, which in turn impacts the entire food - web and limits biodiversity in grasslands.

Answer:

Loss of topsoil