Explanation

Step 1: Full.
Start with the full backup.
Step 2: Diff_20160503_1700.bak
Followed by the most recent differential backup.
Step 3: Log_20160503_1900.bak
And finally the most recent log backup (the only log backup done after the most recent differential backup).
References:
https://docs.microsoft.com/en-us/sql/relational-databases/backup-restore/differential-backups-sql-server