Although art historians typically attribute Rembrandt's large collection of self-portraits to his prolific nature,
recent scholarship published by numerous art history journals
have revealed that the seventeenth-century artist had often directed his apprentices to copy his own self-portraits as a means of improving their drawing techniques.
A.
have revealed that the seventeenth-century artist had often directed his apprentices to copy his own self-portraits
B. has revealed that the seventeenth-century artist
has often directed his apprentices to copy his own self-portraits
C.
has revealed that the seventeenth-century artist often
directed his apprentices to copy his own self-portraits
D.
have revealed that the seventeenth-century artist would have often directed his apprentices to copy his own self-portraits
E. has revealed that the seventeenth-century artist
had often directed his apprentices to copy his own self-portraits
We need a singular verb to agree with the singular subject : Scholarship.
in B - Use of present perfect tense indicates the Rembrandt is still directing his apprentices - which is not possible
in E - Use of past perfect is uncalled for as there is no verb/action sequencing