Realative dating age of rocks
Clearly, Sedimentary Rocks A were deposited and deformed before the Volcanic Dyke intruded them.
Although there might be some mineral differences due to the difference in source rock, most sedimentary rock deposited year after year look very similar to one another.
The most obvious feature of sedimentary rock is its layering.
This feature is produced by changes in deposition over time.
Levels of carbon-14 become difficult to measure and compare after about 50,000 years (between 8 and 9 half lives; where 1% of the original carbon-14 would remain undecayed).
The question should be whether or not carbon-14 can be used to date any artifacts at all? There are a few categories of artifacts that can be dated using carbon-14; however, they cannot be more 50,000 years old.