Which of these would manually trigger a synchronization for Azure AD Connect through PowerShell?

Which of these would manually trigger a synchronization for Azure AD Connect through PowerShell?

• start-adsyncsynccycle -policytype alfa
• start-adsyncsynccycle -policytype delta
• start-adsyncsynccycle -policytype all
• start-adsyncsynccycle 

EXPLANATION

You can still force an export by using the synchronization service manager.
A server in staging mode continues to receive changes from Active Directory and Azure AD. It always has a copy of the latest changes and can very fast take over the responsibilities of another server.
If you make configuration changes to your primary server, it is your responsibility to make the same changes to the server in staging mode.
start-adsyncsynccycle -policytype delta

SOURCE

https://docs.microsoft.com/en-us/azure/active-directory/connect/active-directory-aadconnectsync-operations