Which of the following layers is needed for operating the proxy of the OSI model?

The application model is referred to as the 7th layer in the OSI model. And, because the proxy acts at the seventh layer, it requires the application layer. Proxies are capable of filtering network traffic based on content such as phrases, keywords, and so on. As a result, a proxy digs down deepest in comparison to a packet's header and revives the data inside the packed.