Wiring help for Caseta in-wall fan control (PD-FSQN)

Hi all,I'm having some trouble figuring out which wires go where—I've done all the electrical in my home over the last decade so I'd like to avoid calling an electrician if possible. I've attached three images. The first one is the new switch with the terminals labeled. The second image is of the previously-installed switch (the neutral was unused (?)). The previous switch was also just a simple switch—no fan control. The last picture is of the box itself. Wire A was connected to terminal A on the old switch. B to terminal B. But that's it. Anyone able to help me decipher what's in the box for me? Thanks in advance! Dan. Image 1: In-wall Fan Control (PD-FSQN)https://i.imgur.com/0dEuALP.jpgImage 2: Previously-installed switch in same locationhttps://i.imgur.com/PEbM0ld.jpgImage 3: Box wiringhttps://i.imgur.com/P3ofYcD.jpg

From what it looks like. "B" Should be connected to the black screw on the PD-FSQN fan control. The "A" to the yellow wire on the fan control. "C" which looks like the neutrals should be connected to the white neutral on the fan control.

The first photo is a light dimmer which will not work for a ceiling fan.