Not less than

[prosaicblabber]

No less an authority than Walter Cronkite has reported that half of all Americans never read a book.

(A) No less an authority than
(B) Nonetheless an authority
(C) Nevertheless authoritarian
(D) Not less an authority than

OA-A

[grockit_andrea]

This is just an idiom issue. The correct idiom is "no less X than Y," or in other contexts, simply "no less than."