I believe the answer is a definition.
Copper has all those characteristics and even works on a Notatem scale.
c. online college and career planning resource you can access once you take the PSAT.
Explanation:
MyRoad is an online platform where college and career planning resources can be accessed when the PSAT has been taken.
It provides an online mentor-ship and guidance for approaching the more robust college life.
The platform allows diverse students to access useful information about their intended colleges.
It also helps in determining career choices and a host of other resources.
Answer: the answer should and most definitely be D.
Explanation: I mean think about it after a while only a few radioactive nuclei are left which means it will dye down after a while which also makes it very boring hope this helps :)