In metalwork one advantage of adhesive-bonding over spot-welding is that the contact, and hence the bonding, is effected continuously over a broad surface instead of a series of regularly spaced points with no bonding in between.
(A) instead of
(B) as opposed to
(C) in contrast with
(D) rather than at
(E) as against being at

My answer: B. Not sure why, but it sounds right.

sogmat wrote:In metalwork one advantage of adhesive-bonding over spot-welding is that the contact, and hence the bonding, is effected continuously over a broad surface instead of a series of regularly spaced points with no bonding in between.
(A) instead of
(B) as opposed to
(C) in contrast with
(D) rather than at
(E) as against being at


oa d

y not b

B: is effected continuously .... as opposed to effected a series ...
D: is effected continuously .... rather than effected at a series ...
(b) is missing a necessary preposition to connect "effected" and "a series"

Moreover for showing contrast or preference...the preferred GMAT idioms are "instead of" and "rather than".....