This was the question I was asked during my project review but still I am clueless about the answer.

The question was, Is there Data Abstraction in C Language? I answered them No. Then, they asked me What is Structure and Union?. I told them, A structure is a collection of variables under a single name. These variables can be of different types, and each has a name which is used to select it from the structure. A structure is a convenient way of grouping several pieces of related information together. Now they asked me, If that is the case then how can we say that there is no Data abstraction in C? I was totally speechless at this. Still now, I don't have the answer for it.

If you guys can help me explain me this, it would be of great help to me. Thank you very much!