When an ordinary piece of steel is put under pressure, the steel compr

When an ordinary piece of steel is put under pressure, the steel compresses; that is, its volume slightly decreases. Glass, however, is a fluid, so rather than compressing, it flows when put under pressure; its volume remains unchanged. Any portion of a sheet of glass that is under sustained pressure will very slowly flow to areas under less pressure. Therefore, if a single, extremely heavy object is placed in the middle of a horizontal sheet of glass of uniform thickness and if the glass is able to support the weight without cracking, then the sheet of glass will eventually.

This is what we know about Glass. A Glass doesnt compress it flows when pressure is put & its volume doesnt change. When pressure is put it slowly flow to areas under less pressure

A says
become larger in size yet still be of uniform thickness. No. It doesn't. the argument doesnt say so.
Now lets see what E says
be thinner in the portion of the glass that is under the pressure of the object than in those portions of the glass that are not under that pressure.
Yes thats true. What will happen if heavy object is placed in the middle. We know Glass doesnt compress it flows when pressure is put So the portion of the glass that is under the pressure will be thinner than other portions.

I don't think that this question qualifies for GMAT type question with 600-700 difficulty level.

(A) Change in size is not under consideration - Out of scope.
(B) Converse of what has been stated in the stimulus - Incorrect.
(C) Comparison with steel is not discussed.
(D) Division into pieces is not discussed - Out of context.

Thus, Answer must be (E)

A. "become larger in size yet still be of uniform thickness"
This option doesn't logically complete the argument because the argument states that glass flows under pressure but doesn't mention it becoming larger in size. It's also not clear how glass could become larger while maintaining uniform thickness.

B. "flow toward the point at which the pressure of the object is greatest"
This is the correct answer. It logically completes the argument based on the information provided. The argument discusses how glass flows when under pressure and how it will slowly flow away from the point of greatest pressure.

C. "compress, although not as much as a piece of steel would"
This option contradicts the information in the argument. The argument clearly states that glass does not compress when under pressure, so this choice doesn't align with the argument's content.

D. "divide into exactly two pieces that are equal in neither size nor shape to the original piece of glass"
This option is not supported by the information in the argument. The argument talks about the glass flowing under pressure, not breaking into two pieces.

E. "be thinner in the portion of the glass that is under the pressure of the object than in those portions of the glass that are not under that pressure"
This is the correct answer. It logically completes the argument by stating that the glass will become thinner in the region under pressure compared to areas not under pressure, which aligns with the concept of glass flowing under pressure, as mentioned in the argument.

In summary, option B and option E could both be considered as reasonable completions of the argument, but based on the information provided, option E aligns more closely with the behavior of glass under pressure as described in the argument.