Pick all that apply

• 1Choice 1.

  Using downloadTask instead of dataTask writes the response to a temporary file instead of piling it up in memory, and the file at the temporary URL you get in the completion callback has to be moved to a permanent location before the callback ends

• 2Choice 2.

  A URLSessionConfiguration.background(withIdentifier:) session lets a system daemon carry on the transfer even when the app is suspended or terminated, and on completion it wakes the app in the background and calls the delegate

• 3Choice 3.

  With allowsExpensiveNetworkAccess = false the request won't run on expensive paths like cellular and hotspots, and the user's Low Data Mode is handled through allowsConstrainedNetworkAccess

• 4Choice 4.

  Background sessions don't support resuming, so an interrupted download has to start over from the beginning

• 5Choice 5.

  Setting isDiscretionary = true on a background session lets the system defer the transfer until power and network conditions are good, which suits large downloads that aren't urgent