An array of tax incentives has led to a boom in the construction of ne

ifyouknowyouknow

This is one of those questions that tests a construction we basically never use in everyday speech, so don't think of this as typical. But yes, in this context we can have quite a bit in between HAS and BEEN, and in more ordinary constructions we often see a modifier in between those words: "has certainly been," "has recently been," etc.

The problem with D is that we really need "so . . . that" to indicate that capital has been SO abundant THAT investors keep looking for new places to build. Notice that SO is dealing with a modifier: abundant. SUCH deals with nouns. I can use it to say the same kind of thing as SO THAT, but the structure has to look different. For instance, I could say "It's so hot today that school was cancelled" or "It's such a hot day that school was cancelled." SO intensifies HOT, while SUCH intensifies HOT DAY.

In that context, D is like saying "Such has the heat of the day been." That's not a thing we say. SUCH only applies to the noun part, not the whole clause, so this isn't saying anything clear.

Why not c. it seems simpler and more clear answer

Adityas544

For C to work, we'd need "such THAT." I can't say "the heat has been such, I stay inside all day." Even with SUCH THAT, this construction doesn't make a lot of sense, as you can see if you add THAT to my heat example. When we use "such that," we are usually talking about what KIND of thing led to our result, not just HOW MUCH of something we've had. So I'd say "capital has been SO abundant that investors . . . ." I'd use "such that" if I were saying something like this: "The NATURE of the investments has been SUCH THAT only specialists can accurately assess the risks involved."