The discovery of glass being expandable and able to be

E is the correct one.

The discovery of glass being expandable and able to be shaped by human breath revolutionized glass working to such an extent that today "glassblowing" has become the generic term for all glass working, whether the glass is blown or formed by other techniques.

(A) of glass being expandable and able to be
(B) of glass that is capable of expansion and
(C) of glass being capable of expansion and that it can be
(D) that glass can be expanded and it is able to be
(E) that glass can be expanded and

What revolutionized the glass-blowing industry? The discovery. Only D & E properly focus on the "discovery" , the rest are nebulous and B even suggests that there is a particular type of glass that has these properties.


A - Awkward and one doubts what was discovered, and "able to be", messed up.
B - Seems to suggest a particular type of glass that is expandable than glass in general - change in meaning
C - un-parallel constructions and mess up
D - again "expanded" and "able to be", changes in tense and also un-parallel
E - Perfect - It talks about the discovery and parallel too "expanded" and "shaped"