Which of the following hypotheses holds that “the more diverse and the greater the number of species in an ecosystem, the better that ecosystem will be able to withstand a threat”?

The diversity-stability hypothesis proposes that ecosystems with higher species diversity are more stable and better able to resist disturbances. This is because diverse ecosystems have more functional redundancy and complex food webs that can buffer against the loss of any single species. The other hypotheses listed relate to plant physiology (Raunkiaer's) or unrelated ecological concepts.