Where would you set a threshold limit in social studio

Which two statement are true when using Journey Data and Contact Data within Journey Builder?
Choose 2 answers

How long does the activation process take for Einstein Engagement Frequency?

A deployment specialist sends an Inbox message to your customer audience "Loyalty Program". The next week, they send a message to the same audience using the Replace Inbox feature, but now that audience has some members that no longer exist. What is the expected outcome?

In social studio how many columns are used in a engage tab (max 30 tabs in a engage, no limit for columns in each tab) and each column contains max 50 accounts)