The development of a new type of manufacturing called 3-D

Howdy! I think I might be able to help a little bit here!



This is an excellent question! It is actually a subtle change that I didn't notice the first time that I read through these answers. Let's look at them:


B. The development of a new type of manufacturing – called 3-D printing or additive manufacturing – will involve futuristic printing machines that can replicate 3-D images and that can lower costs considerably by greatly expanding where products can be made and who can make them.

E. A newly developed type of manufacturing called 3-D printing, or additive manufacturing, involves futuristic printing machines that can replicate 3-D images and that will lower manufacturing costs considerably by expanding where products can be made and who can make them.

Honestly, I am a bit disappointed with this answer choice. You are correct that the meaning has been changed. In (B), we can see that this technology has the ability to lower costs and replicate 3-D images. In (D), the meaning is slightly different. The technology still has the ability to replicate 3-D images, but doesn't yet have the ability to lower costs. That will happen in the future.

Now maybe, in (B) this idea is implied with the use of "will involve," but I think this is a very very weak inference and likely not true.

Ultimately, I think this is a flaw in the question. Whoever wrote this questions probably didn't notice the change that they were making to the sentence in (E). I don't see any reason for the change in meaning, unless the question writer expects us to have outside knowledge about 3-D manufacturing. I know that it is pretty expensive at this point, and it is not good for a lot of uses because it is so expensive. But the GMAT would never require us to have this kind of knowledge to choose a correct answer.

I think the safest thing to say here is that the answer choice is slightly flawed. The question writer made a mistake that alters the meaning of the sentence. The best wording of answer choice (E), and to make this question truly beneficial for GMAT prep is as follows:

A newly developed type of manufacturing called 3-D printing, or additive manufacturing, involves futuristic printing machines that can replicate 3-D images and that can lower manufacturing costs considerably by expanding where products can be made and who can make them.

I hope that helps!