I would say the best answer is A, he hides behind a tree. I was in between A and D, but one can run in a park.
B wouldn't work because him being dressed in ordinary street clothes doesn't show that he's afraid of something.
C wouldn't work because although yes, he was panting, that could mean that he's just tired; not necessarily, scared.
The man hiding behind the tree is the best evidence for the conclusion of him being afraid of something. Also in the passage it states, "....he moved behind a tree. Seeming not to notice my presence, he stood with his back against the trunk, panting."
It is all about discoveries: Antigone discovers her punishment for trying to bury her brother's body: she will be buried alive. The unusual cruelty of such punishment is apparent to the reader. The sentry discovers Antigone's actions. Creon discovers the event himself and is enraged against Antigone. Ismene, Antigone's sister discovers that she no longer hates her late brother and that she also wants him to be properly buried.
The many discoveries force the audience to reflect upon the fact that there are hidden truths and realities behind someone's actions sincethey can compare Creon's view of civil laws and Antigone's view of Divine laws and understand that unless civil laws are moral, they are not to be obeyed.
I am not completely sure, but I would say that these events serve as omens to alert the characters and the audience that terrible things will soon happen. It is a form of foreshadowing.
