Capacity tier.
This one may be tricky than on first glance. There are 2 retention periods referenced in this question, dailies are set to 31 days whereas a weekly GFS full backup are kept for 14 weeks. Since the question is asking for a backup that occurred during the week of Jan 1st, not specifying a specific date, then in theory that weekly GFS (with a retention of 14 weeks) meets that criteria and would be stored on the performance tier, right? However, the settings for this SOBR are set to "move" backups older than 21 days - so with that in mind, it's been well over that amount of days (Jan 1st to Mar 20th), meaning the weekly GFS restore points from that month of Jan were moved to the capacity tier.