Fact 1: Scraping oneself on a contaminated object may cause infection. Fact 2: Contact with infected blood, contaminated needles. Given the two facts above, answer the question "Getting scraped with what can give oneself an infection?" with the following options: - deoxyribonucleic acid - a knife with sanitized dirt - Roundworms. - harmful substances - Roundworms - a clean needle - a clean scapel - an infected needle
A:
an infected needle