The recommended update frequency for the local product inventory feed is daily.
The correct answer is: Daily
Explanation: To ensure the most accurate and up-to-date inventory representation, it’s essential to update your feed daily. Not only does this allow for real-time accuracy, but you also have the flexibility to submit updates several times within the day for specific inventory segments. This daily update ensures that customers view the most current store inventory and optional pricing.
Read more here: https://support.google.com/merchants/answer/7371791