When testing code for correctness, it always makes sense to . Select one: a. identify boundary cases and test them b. assume invalid input will never occur c. check all cases by hand d. test at least one branch of each test case

a. identify boundary cases and test them

Explanation:

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this

i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.

since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.