Here's why:
* Oscar for Screenplay: Chayefsky won an Oscar for Best Writing, Screenplay Written Directly for the Screen for the movie "Network".
* George C. Scott Declining Oscar: George C. Scott, who played the main role in "Network", famously refused to accept his Academy Award for Best Actor. He felt the awards ceremony was a "two-hour meat parade" and a "self-serving pat on the back".
* Directed Marlon Brando: While Chayefsky wrote the screenplay for "Network", he didn't direct it. However, he did write the script and direct Marlon Brando in the TV movie "The Americanization of Emily" (1964).
So, while you might not have *directed* Marlon Brando in the same movie where George C. Scott declined his Oscar, the clues point strongly to Paddy Chayefsky as the most likely answer.