Association has got two meanings ... one -- a group of people organized for a joint purpose.forexample ,"the National Association of Probation Officers" ....and two --a connection or cooperative link between people or organizations. For example , "he developed a close association with the university" Now1st being:
"a group of people organized for a joint purpose". (For example,"The National Association of Probation Officers".)
And the 2nd being:
"a connection or cooperative link between people or organizations". (For example, "He developed a close association with the university".)
Now, I hope you would be able to choose which one to use... ifIf not , then "ABC is a ...." would be the best choice .