Pick all that apply

• 1Choice 1.

  A timeout means the server didn't receive the request, so sending the same request again as-is is safe

• 2Choice 2.

  If the request carried a client-generated idempotency key, retrying with the same key won't make the server create a duplicate payment

• 3Choice 3.

  Show the user a "confirming" state instead of "failed," settle the result through a payment status lookup, and only then show success or failure

• 4Choice 4.

  timeoutIntervalForRequest is the time by which the whole request must finish, and timeoutIntervalForResource caps the idle time with no data flowing

• 5Choice 5.

  When retrying, use exponential backoff with jitter so clients don't stampede the server while it's recovering