Given the task definition and input, reply with output. In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".

[header] How to avoid h1n1 [title] Get vaccinated against h1n1. [step] You are most likely to contract h1n1 during flu season. The cdc warns that every flu season is different and thus vaccinations are tailored for the season. <sep> (A) However, some vaccinations are more likely and safer than others. [substeps] You do not need to be a member of a group of people infected with the disease, or you risk exposing the sick person to h1n1. (B) You should still be vaccinated for h1n1 in groups of 6 to 12 months. Medicine should be used in non-vaccinated individuals during flu season. (C) Flu season is characterized between october-may (in the us). During that time, you should receive a flu vaccine, especially if you are 65 or older. (D) Make sure that you get them before you skip the winter vaccination. This is especially important if you live in the united states or canada because the diseases are usually more common for these countries.
C