We can intervene in several areas of the chain of infection in order to stop a sudden, current outbreak. All of the following are effective early strategies except a. Vaccinations
b. Washing hands often
c. Quarantine
d. Wearing masks

If the outbreak is current, the answer is A, Vaccinations. This is because current infections will likely mutate to become resistant to previous vaccines. While all of the other methods work for any infection (by keeping it from spreading from host to host), vaccines could not be produced safely and effectively at the beginning of an outbreak.

We need a b c d ur answer