Tying two notes changes them - how to fix

I have input this measure of treble clef music in 4/4:
Screen Shot 2020-04-06 at 12.28.46 PM.png
I want to tie together the last C’s you see.

When I click on the first of the 2 C’s (the eighth note) then hit the T key, I get this, which is NOT what I want:
Screen Shot 2020-04-06 at 12.28.46 PM.png
How do I change the last two notes of the second screenshot into a half note?
Screen Shot 2020-04-06 at 12.30.03 PM.png

A. Look through Notation Options > Note Grouping and set global options to suit most of your recurring needs.
B. For the rare exception that isn’t covered by setting satisfactory Notation Options, use Force Duration.

I see. I didn’t know about that particular prefs window. I just went in there and adjusted several examples to my preferences, which hopefully will take care of this in the future. Thank you!