Producers are called producers because when they take in carbon dioxide and water, and they produce glucose and oxygen. Animals need oxygen to survive and producers are the reason that all of the animals on earth haven't used up all the oxygen in the atmosphere. We need producers to survive, otherwise the Earth would be carbon dioxide rich and we humans couldn't breath it.
B - When many individuals of the same species are available for mating. And C - When the individuals live in a stable environment in which they thrive.
