What is the correct way to figure out the version of Office installed?

Question

For Office 2010 & later, what is the correct, supported, always right, best, best, best way to determine:

1. What version of Office (Word) is installed?
2. What its bitness is?

The registry entries

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\WINWORD.EXE

and

HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\App Paths\Winword.exe

both have the path to the winword.exe file. Do I use that and read the EXE to get the version & bitness?

Also, what if those two registry entries differ?

Note: I am not asking best (opinion - not allowed here), I'm asking correct (what Microsoft has stated - fact - allowed).