aback

IPA: ʌbˈæk

(archaic) Towards the back or rear; backwards.
(archaic) In the rear; a distance behind.
By surprise; startled; dumbfounded. (see usage)
(nautical) Backward against the mast; said of the sails when pressed by the wind from the "wrong" (forward) side, or of a ship when its sails are set that way.

Examples of "aback" in Sentences

Nothing to be taken aback about.
Even the police were taken aback.
I was a bit taken aback at first.
I was taken aback by the telegram.
I was a little taken aback there...
I was taken aback by that response.
The Hotline people are taken aback.
Babe is taken aback by Josh's declaration.
I was taken aback by the novelty of the fact.
But was taken aback by the lack of mainstream coverage.
But then they see the finished works and it really takes them aback, which is great. "
Options B and D are not correct as the word 'aback' means to get startled by something and does not means the same as the word 'back' which is used in the answer choices B and D.
As I read your stories and especially your friends who so generously comment I am taken aback (is aback a word?) by the generous sharing of wisdom you receive from your friends at French-Word-A-Day.
The richness and elegance of the church took me all "aback;" it was so entirely different from anything I had seen, that it was difficult to decide whether I was most charmed by its novelty or its beauty.
Hillary grew up in this culture, so yes she was taken "aback" by these comments; you, others, and obama being so shallow minded and dismissive of someones culture and values is ignorant. obama will never be President.