im not sure what u mean dog with the c and t region stuff.
If youve taken a home test, you would have noticed the two regions, as they are on every THC assay kit. You couldnt miss it.

Theres a C region ("control") and a T region ("test"). A line appearing in the C region indicates the test is functioning properly. If the C region has no line, the testing device is defective or the test wasnt performed properly.

A line appearing in the T region is a negative. Intensity does not matter.

If the T region remains blank, its a positive.