Bounding Box

++ EDITED REPLY

Adding to the discussion,

Be aware that Acrobat is a PDF editor, not a Word Processing editing program.

As such, when you open the "Edit Tex & Images" tool, you'll notice that there is no feature to actually split a box of text, but you can manually select  and cut the desired text from that paragraph; create a new text box and paste that chunk of text there.

Note also that, while editing a PDF document in this manner, the image fields and  other text boxes won't reflow the page content automatically.

You'll need to do that manually in order to fit every element on that page... not very convenient but that's one way of working around it.

The easier way would be to make all of this content editing in Word before converting the .doc file to or saving as PDF.

However, since you already created this PDF from Word, when you edit this document in Acrobat, you may use this keyboard shortcut combination "CTRL+U" to display a grid.

This grid  will aid you visually on where to move the desired text boxes in relation to the page content and other objects.