The correct answer is A. When free hydrogen ions and free hydroxyl ions are removed from solutions of acids and bases, the acidic and basic properties disappear.
The strength of the acid or base depends upon its degree of ionization. Since different acids and different bases dissociate or ionize to different extent in water so their degree of ionization is also different. Strong acids and strong bases ionize in water completely while the weaker acids or bases ionize partially. Ionization of the weak acids in water are in equilibrium. The degree of ionization is the ratio of the number of ionized molecules to the number of molecules which are dissolved in water. In case of acids the ionized molecules are hydrogen ions and in case of bases hydroxyl ions.
D) The Earth was hit by a one or more objects from space 65 million years ago. The iridium layer shows an extraterrestrial cause for the extinction at the Cretaceous Tertiary boundary, discovered by the Alvarez family. The first discovery of this layer was in the Bavarian alps, in Lattengebirge. The Alverez family proposed that the extinction of the dinosaurs was due to a large meteor hitting the Earth at the end of the Cretaceous period, marking the KT boundary with this clay layer which has a high content of iridium. Iridium is not common on Earth, but is common in meteors.
Biodiversity boost the eco-system which essentially is the same reason we have plants without biodiversity we wouldn't have plants or trees. Therefore we wouldn't have oxygen so the more we kill the Eco-system the more our planet and life becomes more and more threatened therefore the more food supply and demand becomes less and less. Which basically leads to extinction. So biodiversity is also helpful for biodegradable products like plastic instead of foam. Essentially recycling basically saves our planet.