Hi Vivek,
based on the scenario described, my understanding is that you as PM do not actually know which (if any) quality control activities the team missed.
What you do know is that the PM recognises the team to be under pressure and stressed because of the hard deadline to be met, so he/she is concerned about potential implications on the quality control procedures. The PM still has no evidence that this is what actually happened. To determine whether the quality control process and related procedures have been carried out appropriately, you need to conduct an audit.
At the same time, there is no evidence from the scenario that this has been previously identified as a risk, and a risk response was planned, which would have called for a risk review, to check whether the risk response has been successfully implemented.
As for the issue log, while not an option provided, I would have not selected it either, because you don't know if there is any issue with the quality control procedures until you perform the audit. So far it is just the PM concern. At least, this is my understanding from the scenario description.
Hope this helps,
Gabriella