Combining atoms at room temperature may be possible one day,

To truly understand this problem, we need to understand the “-ing” ending for verbals. First, it is worth noting that a verbal is NOT a verb – so it doesn’t have to follow verb conjugation rules. Verbals are words that at first glance might look like verbs but function as nouns or modifiers. Verbals with “-ing” suffixes are actually not “continuous present tense verbs” at all; instead, they are either gerunds (in other words, nouns… for example, “Running is something I like to do) or present participles (in other words, adjectives… for example, “running water”.) Verbals are not a “weaker” verb form at all, but a different construction altogether. However, the fact that verbals ending in “-ing” can, depending on context, be either a noun or an adjective is the key to unlocking this problem.

Both answer choices A and E contain the profoundly ambiguous phrase “combining atoms.” Notice how this phrase could mean either “atoms which combine” (using the present participle form) or “the act of combining atoms” (using the gerund form.) With the first option, atoms is the subject of the sentence, while the second option the gerund “combining” is the subject. This drastically changes the meaning, therefore eliminating both A and E as possible candidates.

Answer choice B can be eliminated because of the phrase “at the temperature of a room.” This implies a specific room, whereas “room temperature” is the idiomatic way of saying “around the temperature humans normally like.” The meaning totally changes. This is an Illogical error.

Answer choice C also contains an Illogical error. The meaning of the phrase “The combination of atoms at room temperature may one day be possible” implies that atom combinations are not possible at room temperature, and if this were true, life as we know it would be impossible. Molecules are a pretty big part of, well, everything.

The only answer remaining is answer choice D. Now, D contains what I call “Convoluted Camouflage” in my classes. The basic idea is this: the GMAT sometimes hides the correct answer by embedding unusual or obnoxious phrasing without containing grammar or logical problems. Many people see the pronoun “It” and get upset because this seems like an ambiguous pronoun with no clear antecedent. However, the phrase “it may be possible to…” is a common English idiom. This is a false alarm intended to trap people, when in fact such a construction is perfectly legal.