Unlike that of earlier works on slavery, Blassingame's innovative study relies not on the records
of White slave owners but on the records of the salves themselves, especially the 70 or so
autobiographies and memoirs that have been preserved.
A. that of earlier words on slavery, Blassingame's
B. that of earlier works on slavery, Blassingame in his
C. earlier works on slavery, Blassingame in his
D. earlier works on slavery, Blassingame's
E. the earlier works on slavery, Blassingame in his

I would like to get answer of this question and explanation as well..
Regards
Deepak