Answer:
A
Step-by-step explanation:
You can already cross out c because they are talking about a march and the story never said anything about a march. You can cross D out because That time is around the 1960's and it wouldnt make sense to say how time has changed from the 1960's if your IN the 1960's. And I think A Does a really good job of explaining what helps to reveal the theme.
Hopefully This Helps!