An atmosphere is a layer of gas or layers of gases that envelope a planet, and is held in place by the gravity of the planetary body.
Starfish: invertebrates
Amphibians: vertebrates
Birds: vertebrates
Octopus: invertebrates
Coral: invertebrates
Fish: vertebrates
Clam: invertebrates
Reptiles: vertebrates
An opaque object is any object that is not transparent (allowing all light to pass through it), or translucent (allowing some light to pass through it.) Knowing this we can auto-matically dismiss option D),B), and C) because these all let some form of light through them so our answer would then be A) because light does not pass through wood like it would the others.
Interspecific competition I believe
