Why would high levels of biodiversity help to make an ecosystem more resilient?

Me ! which of the following is an environmental concern of genetically modified foods? a) crops that are drought resistant are introduced providing food regardless of the unpredictable weather b) reduction cost of production for the crops c) an important ingredient may be introduced in a strain of rice for the poor who depend on rice as a primary food d) toxic substances produced as a pesticide may be consumed by unintended species