Seeing as Peter is male, he's seeing a counselor (which indicates mental/emotional/psychological issues) and has been referred to a urologist, I'd say his problem is erectile dysfunction, or choice #2.
Protein. im absolutely certain
The ensemble of formations and folds in a single linear chain of amino acids sometimes called a polypeptide constitutes the tertiary structure of a protein. Finally, the quaternary structure of a protein refers to those macromolecules with multiple polypeptide chains or subunits.
Answer: The cause can be something that causes the problem and the effect is what effected it. If something caused the population to go down the effect would be death rate or birth rate.
Hope this helps!