The success of the new office development will depend not only on the

Now that the contest is over and this has appeared on the QOTD, I'll add my solution to this relatively easy question. Peeking at the answers, we see a few obvious changes:

1. "on" - Because this pronoun doesn't exist and then does and then moves around, we will likely deal with parallelism. Looking at the sentence, we see the "not only [A] but also [B]" structure, so this will govern the parallelism here ([A] and [B] must have the same structure). [A] is a prepositional phrase "on the architect's skill...", so [B] should be as well. With this we can eliminate answers A and B for not having prepositional phrases. We can also eliminate E because the structure is "not only on the architect's skill ... but on also the legal team's ability ..." and this splits up the prepositional phrase in an awkward way that also breaks parallelism.

2. "in securing"/"to secure" - We have to decide if an infinitive or a prepositional phrase with a gerund better fits the meaning. Almost always pick the infinitive over prepositional phrase containing a gerund. This is one of the few rules that you can actually follow 100% of the time without analyzing it. (Side note: don't always just eliminate "being", unless it is "to be" vs. "[preposition] being" - you should better analyze it any other time.) With this we can eliminate B and D.

Based on these alone, C must be the answer. However, there is also the "its"/"their" difference. For this, we need to find the referent of this pronoun and decide if it is singular or plural. So, what has a "claim of eminent domain to secure the waterfront property"? We only have a few potential nouns and all of them are singular, so we should choose "its", but I want to discuss this further because I think it creates a problematic meaning.

First, there are two fake nouns here. "architect's" and "legal team's" are NOT nouns because they are possessive. A pronoun cannot refer to either of them. See OG 13 #28 and #68 for more examples.

Second, there are a lot of nouns that cannot logically fit because they cannot have a claim of eminent domain. These are "success", "architect's skill", "his vision", "innovative design", "legal team's ability", and "eminent domain".

Third, "eminent domain" and "waterfront property" are problematic because they are part of the same phrase as the pronoun, so they cannot logically be the referent since otherwise they would be having claims to themselves.

The only remaining noun is the new office development. This might possibly have a claim to the waterfront property, but it's hard for me to make sense of that meaning because it hasn't been built yet. We are basically saying that a nonexistent building has a claim to the waterfront property that it might some day be built upon. In my opinion, that creates an invalid meaning, leaving us with a pronoun that doesn't have a defined referent. "it" probably should refer to the company who is undertaking this project, but that company is undefined here, creating an ambiguous pronoun (not because of too many potential referents, but because there is no referent). (Side note: don't eliminate an answer for an ambiguous pronoun unless you have exhausted all other possibilities - ambiguous means unclear, not wrong, and it is better to be unclear than wrong.)

It's possible that the author intended to have "its" and "their" refer to the legal team, since there might be singular/plural ambiguity because it is a collective noun. However, the legal team in this sentence is NOT a noun, so that would be invalid. If we wanted the pronoun to refer to the legal team, we could say "but also on the ability of the legal team to exercise its claim of eminent domain to secure the waterfront property". Now, "legal team" is a noun and a potential referent of "it".