What is the reason for administering multiple doses of the reversal agent or antidote (naloxone) for opioid overdose?

a. The half life of naloxone is shorter than the half life of opioid drugs.
b. Naloxone binds to µu receptors as a competitive agonist .
c. Naloxone is an effective oral opioid antagonist used to reverse acute opioid overdose.
d. Naloxone is an effective oral opioid antagonist used to reverse acute opioid overdose .