its good question but not posted in detail. since you have not provided the ful question, D and E are not known why they are wrong.
C, your choice, is a clear wrong because it is in passive. try avoiding passive mood, selecting active.
A is not a complete. after and "Arther’s coffin marked with the inscription" should be a clause but it is not. therefore it is wrong..
so remains B.
[quote="MBA2ran"]According to medieval monks , the remains of King Aurther and Queen Guinevere were found at Glastonbury Abbey in A.D 1191,
and Arther’s coffin marked with the inscription(in Latn): “Here Lies Arther, The One and Future kingâ€