You will make a terrible … in introducing her to your parents.
(a) blunder
(b) slip
© error
(d) defect
The answer is listed as “blunder”: however, I would say that correct answer is “error”.
According to the Visual Thesaurus: Error also means a wrong action attributable to bad judgment or ignorance or inattention.
Both “blunder” and “error” would be correct in that sentence.
Interesting that the BNC gives 4 per 1 million words for “terrible blunder” and for “terrible error”.
I agree with Jamie, either word is fine there.
So, this page is wrong:
Hi, LLewellyn
I guess the test creator made a terrible error (or blunder) while compiling the test 
Doesn’t ‘terrible mistake’ sound more natural?
Yes.
I agree that ‘terrible mistake’ would be a much more commonly used collocation.
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Not quite sure why you included search results for ‘terrible burden’. Did you mean to write/search for ‘terrible blunder’?
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Terrible burden ??? :shock: What burdens you, Molly ? 
I was listening to Eric Burden at that mo’. :lol:
My as*. 
As for me, I wonder whether that site has become partners with this site. :lol:
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