Answer:
People who are interested in the causes and cures of diseases
Explanation:
From the newspaper headline, the newspapers are trying to connect with people who have an interest in the causes, prevention and cure of diseases because the headline is celebrating World AIDS say.
AIDS is an acronym for Acquired Immune Deficiency Syndrome and is a disease that attacks the immune system of an infected person, weakening it and is an advanced form of HIV which has no medical cure as of time of writing.
It is whom. You can only use who if you can replace is with he or she.
That answer is b) so that you can communicate effectively
