IDIOM tested >> CONSIDER X Y << this construction is strict and not interchangeable with incorrect format CONSIDER X AS Y or CONSIDER X to be Y etc.... ...
In contrast to Walt Whitman,
Ezra Pound considered that late 19th-century American poetry is not a distinct formal repertoire informed by its own ideology, and is essentially an outgrowth of the British poetic tradition.
Option A is presenting idea what Ezra Pound considered. Therefore, verb tense past or past perfect is required.
A. Ezra Pound considered that late 19th-century American poetry
is not a distinct formal repertoire informed by its own ideology, and
isB. Ezra Pound considered late 19th-century American poetry not
as a distinct formal repertoire informed by its own ideology, but
C. Ezra Pound considered late 19th-century American poetry not a distinct formal repertoire informed by its own ideology, but
D. it was considered by Ezra Pound that late 19th-century American poetry
is not a distinct formal repertoire informed by its own ideology, but -- same error as in A.
E. late 19th-century American poetry was considered by Ezra Pound not
to be a distinct formal repertoire informed by its own ideology, and is -- idiom error.