A classic latency histogram's boundaries are 0.1, 0.5, 1, and +Inf seconds. One 0.3-second request is observed. Which bucket counters increase?

1. Only the +Inf bucket
2. The 0.5, 1, and +Inf buckets
3. The 0.1 and 0.5 buckets only
4. Only the 0.5 bucket