which of the following statements is true?

a. a producer must be a plant.

b. humans that prepare their own means are producers.

c. a producer usually obtains food by hunting other organisms.

d. consumers depend upon producers for food.

The answer is D since this is true about consumers.

the correct option is option a

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.