The diagram below shows a cross section of rock layers.
layer 3 has been affected by igneous intrusion. this indicates that
a. the shale was deposited before the igneous intusion occurred.
b. the shale was deposited after the igneous intusion occurred.
c. contact metamorphism only happens underneath the igneous intrusion.
d. the igneous rock was deposited before all other layer.
see diagram in the picture you