A noun becomes a compound noun when it combines with another noun using the conjunction ‘
and’ and is plural in number per se.
For example: There is a brother and a sister in this class, is wrong because, a sister and a brother put together becomes a compound and plural noun entailing a plural verb. The correct version is ‘There are a sister and a brother in this class.’ Hence You can dump A and D.
B is the correct one; here ‘
that’ is the subject of the subordinate clause; ‘
that’ stands for both the laws and the word ‘
each’ indicates that the laws individually and jointly are valid and consistent.
C is wrong because of using the unidiomatic ‘
both of which are each’. Each is an unnecessary intrusion
E is wrong becos of saying that the laws are each valid ‘
or’ consistent. Valid ‘
or’ consistent distorts the intended meaning of the original passage.