Question about HDTV and PC cables for optimum resolution

I purchased a refurbished Toshiba 24SL410U TV recently and I have hooked it up to my desktop PC with an HDMI cable. This cable is split - HDMI Type A on one end and Type C on the other.

After purchasing cables and such to hook it up, I find myself unhappy with the resolution that it puts out. On the PC, it puts out 1360x768. Everywhere I look, I find that this TV (which is 24") should be capable of expressing 1080p resolution, but if I try to do so I find that I am woefully unable to do so.

I've tried fiddling with settings in both my video card (which is an NVIDIA GeForce GTX 550 TI) and the computer and nothing seems to help... I know the TV is capable of better graphics, since I've used it to play video games using the 2nd HDMI port. I already tried switching ports in case THAT was the issue...

I'm wondering if the HDMI cable is my issue? Does HDMI Type C render less resolution? Any suggestions would be appreciated. Thanks!