Hi Lucil.
It is a BW only machine. Grayscale is BW, the printer has white paper and Black toner.
Less dense toner just shades it as Grey.
There is no option to choose BW only because it s nearly useless
Take for instance this photo
Printed as Grayscale
Printed BW
All a BW option would give you is solid black in any place there was anything but an absence of data.
Grayscale uses shades of grey to convey the tones and Black to convey Black.
The only time somebody would prints color as solid black would be in specific cases, and never a photo. Drafting Documents mostly.
The other would be a white background and light colored text, which is fine digitally, but not in print due to CMYK versus RGB, and of course the absence of backlightling.
Acrobat/Reader has a few places beyond what is in that video too. If you choose the File > Print menu, select the printer then go to Advanced make sure Let Printer Determine color is checked, or in Acrobat its in Advanced > Color Management
Word has no real color options, but to get to the driver in Word when printing it is File > Print > Printer Properties > Image Options but this is not a color printer so you are quite limited.
Word can (in some versions) convert a job to Grayscale via Page Layout > Colors You could in theory use the Custom option to create a Black only setup
Also, notice that in both programs, BW and Grayscale are entirely interchageable, as they are in the Xerox driver, and the HP driver in the video by Adobe