Answer:
Sequence A-D was disturb by crustal movement after it was deposition. We have evidence in given cross section that sequence A-D was disturb by crystal movement just see above this sequence there is conglomerate bed which indicates it is uncomformity and that below uncomformity plane all beds are inclined so it clear evidence that sequence A-D got disturbance by crustal movement.
Explanation:
Sequence order and principal are given below.
one can order the event in any given cross section on the basis of apply some principal like order of super position, principal of cross cutting relationship, principal of inclusion, principal of original horizontality etc. Order of superposition tell us that if rock is undeformed then older rock would be at bottom and younger at top, principal of cross cutting relationship tell if some igneous body intruded in some rock layer so it mean that layer is older than age of intrusion.
