(A) so gradual as to be indistinguishable
(B) so gradual they can be indistinguishable
(C) so gradual that they are unable to be distinguished
(D) gradual enough not to be distinguishable
(E) gradual enough so that one cannot distinguish them
Solution:
Idiom*
The correct usage are: “so cause as to effect” or
“so + cause + that + effect”.
Hence, B can be eliminated.
Secondly, “cause + enough + to + effect” is the correct usage.
Hence, D and E can be eliminated.
C is wordy in “they are unable to be”
A is the best choice.
Sentence Correction - 1000 Questions with Solution:
