The correct answer is C.

It’s always very difficult to see whether a cut-off low extends to the surface without the aid of surface observations. The airmass RGB and WV and VIS imagery can only provide evidence of cloud types as seen from above, while surface observations give clues as to whether there really is any cyclonic rotation on the ground. It can be helpful to look for thickening of the cloud on the airmass RGB; the yellow/warm clouds will become lighter or white. Also use animations to see if the thicker clouds are starting to rotate. Sometimes a COL is associated with a closed low at the surface or possibly a cold front and ridging high pressure. The airmass RGB is, by far, the best product to use in this situation.