Answer:
I think the answer for your question is the letter c
Inbreeding can destroy the genetic variation that we get when two genetically different people reproduce. This can increase chances of birth defects.
Scientists use the pH scale to measure how basic or how acidic a solution is. If a solution is measured at a 7 on the pH scale, the solution is neutral. Any solution that is measured less than 7 is more acidic, while any solution measured more than 7 is is more basic.