Gone are the sharp edges and jutting planes of styles from former eras; instead, designers of everything from cars to computer monitors have adopted a cornerless style of smooth surfaces and curves that is
more ergonomic, conforming to the shape of the body rather than flaunting shape for its own sake.
Option Elimination -
The more complex the questions get, the more we need to look at the meaning. I guess then the better strategy would be to understand the meaning in all questions as we'll not be indicated by some trigger that now we are about to see a difficult question on the actual exam.

. If we do not understand the meaning, we look at options that option E is a wonderful deception (with the right more than idiom on the surface) and option A is on the surface looking ugly (if we go by blind more, rather than - which is a strict no-no) in the right answer.
As someone rightly pointed out in the explanation by Ron. Here, the idea is that the "cornerless style" is more ergonomic. Than what? "Than" the sharp edges. How is it more ergonomic? Because the cornerless style confirms to the shape of the body (which body? The car or computer). Rather than (the sharp edges) flaunting shape - have we seen the old cars? We can see rectangular or whatever shapes very clearly. We use "rather than" to show preference between the choices. More importantly, when we answer "how," "when," "where," and "why" we need adverbial. Comma + ING is adverbial. Comma + ed is not adverbial - Ed will always modify nouns (so option B is wrong anyway).
Option Elimination -
(A) more ergonomic, conforming to the shape of the body rather than flaunting shape - Correctly conveys the meaning and is grammatical + idiomatically perfect. Learning, look for the meaning in the first place so that we don't cross off the ugly-looking correct options.
(B) more ergonomic, conformed to the body's shape and not to flaunting shape - "Ed verbal" can't answer "how." We need adverbial - comma+ING.
(C) ergonomic, more conformed to the shape of the body and not to shape flaunted - same "ed verbal" issue. and "more" and "and" - wrong.
(D) ergonomic, conforming more to the body's shape rather than shape flaunted - more rather than - wrong.
(E) ergonomic, conforming more to the shape of the body than flaunting shape - deceptive wrong option. It means how is it "ergonomic." By confirming more to the shape of the body" than "conforming" flaunting shape. The intent is that it's doing X rather than Y and not more X than Y.