Someone help me please

What is a food chain? a.different animals located in different communities b. energy transferred from the sun to plants and then to a series of living things c. rows of crops, such as lettuce, in a field d.animals using one another as food for energy and growth

Need ! will give 20 points! what are two ways that diatoms differ from slime molds? the external coverings of diatoms are made up of (silica, chitin or peptidoglycan), while slime molds have cell walls containing (silica, peptidoglycan or chitin). diatoms are (chemoheterotrophs, photoautotrophs or chemoautotrophs) because they make food through photosynthesis, while slime molds are (heterotrophs, phototrophs or autotrophs) because they eat decaying plant matter.

Which component cannot be part of this strand?