Which of the following statements about migration is true?
a. Migration is always from one region to another.
b. Animals always migrate within a region.
c. Migration always negatively impacts an ecosystem.
d. Animals migrate for various reasons.
Please select the best answer from the choices provided

Compare the lunar phase of the waning crescent to the waxing gibbous. the waning crescent is increasing in illumination and the waxing gibbous is decreasing in illumination. the waning crescent is decreasing in illumination and the waxing gibbous is increasing in illumination. the waning crescent is more than half illuminated and the waxing gibbous is less than half illuminated. the waning crescent is more than half illuminated and the waxing gibbous is more than half illuminated.