Radioactive minerals found in sedimentary rocks are the outcome of the weathering of igneous rocks. Dating the sedimentary rock would only reveal the time in which the magma cooled to form the igneous rock, not the sedimentary.
That would be B. There are more and more technologies coming out and more and more hackers to hack that new tech. And don't forget how the government tried to force apple to unlock a phone. It was for the best, but still. Hope this helps and have a nice day!
(-3-3 root of 2, 0) (-3+ 3 root of 2,0)