Which tool should you run?

A company has an Office 365 tenant.
You need to monitor Active Directory synchronization.
Which tool should you run?

A.
ldFix

B.
Office 365 Health, Readiness, and Connectivity Check

C.
Microsoft Remote Connectivity Analyzer Tool

D.
Synchronization Service (MIISClient)

Explanation:
https://www.cogmotive.com/blog/migration/setting-up-dirsync-between-active-directory-and-office-365

NOTE: This could be both idFix. It could be used before hand to check if a sync would work and to fix it.