If your doctor told you that you have strep throat, you could conclude that you are infected with which type of pathogen

The correct answer is bacteria, more precisely, you're infected with Type A Streptococcus bacteria that causes Streptococcal pharyngitis. That's basically where the word strep comes from. It's pretty common and usually the infection lasts for about 10 days, sometimes even less, a week maybe. It's rarely treated aggressively with antibiotics and is prevented by washing hands regularly.