In Kabul, it rarely rained in the summer. […] But it rained the afternoon Baba took Ali and Hassan to the bus station. Thunderheads rolled in, painted the sky iron gray. Within minutes, sheets of rain were sweeping in, the steady hiss of falling water swelling in my ears.
Which of the following is the MOST appropriate explanation of Hosseini’s use of rain as a symbol in this passage from chapter 9?