The major cause of species extinction is

A. agricultural activities
B. extraction (including mining, fishing, logging)
C. development (human settlements, industry)
D. habitat loss and degradation
✅ The correct answer is option D.
Species endangerment and extinction have three major anthropogenic causes—overhunting or overharvesting; introduction of nonnative species, including the spread of disease; and habitat degradation or loss. All three causes probably were factors in prehistoric as well as modern times.

The unit of the light year is used for measuring

A. speed of satellites
B. speed of ships
C. distance between bodies in the universe
D. speed of rockets
✅ The correct answer is option C.
A light year is a way of measuring distance. That doesn’t make much sense because “light year” contains the word “year,” which is normally a unit of time. Even so, light years measure distance. You are used to measuring distances in either inches/feet/miles or centimeters/meters/kilometers, depending on where you live.