I think the answer your looking 4 is B
HOPE THIS HELPS
#Optimist
Answer:
If the hydronium concentration increases, the pH decreases, causing the solution to become more acidic. This happens when an acid is introduced. As H+ ions dissociate from the acid and bond with water, they form hydronium ions, thus increasing the hydronium concentration of the solution.
The greatest cause of the worldwide loss of species is human activity. I think