Some opioid supplies are now being laced with a non-opioid substance that is slower acting, extending the euphoric effect of opioids, but does not respond to naloxone treatment during overdose. This substance is now present in more than half of all fatal overdoses in British Columbia. What is that substances?
a. Benzodiazepines
b. Nitazenes
c. Carfentanyl
d. Xylazine