mberkowitz wrote:
had the question read "Noting that the price AND SCARCITY of oil and other fuel components, a major factor in the cost structure of an airline, have risen", would the plural construction be correct (since and joining two nouns pluralizes the sentence)?

Noting that the price AND SCARCITY of oil and other fuel components, a major factor in the cost structure of an airline, have risen

Stacey Koprince wrote:Received a PM asking me to respond to akhp77's question about "Y," as constructed with the correct answer.

Full sentence with correct answer:

Noting that the price of oil and other fuel components, a major factor in the cost structure of an airline, will continue to rise, the company management was pessimistic about the outlook for the upcoming quarter.

Here's the structure of this sentence:

Noting [that-modifier, sub-modifier, remainder of that-modifier], subj verb [2 prepositional phrase modifiers].

or:
Modifier, sub-modifier, rest of first modifier, subj verb modifiers

The core of the sentence is:
the company management was pessimistic

The stuff before that core = modifiers. The main modifier before is:
Noting that the price of oil and other fuel components will continue to rise

Within that modifier, there is another modifier, modifying "the price":
, a major factor in the cost structure of an airline,

After the core, we have two prepositional phrases; they are also modifiers. Each modifies the preceding word:
about the outlook modifies pessimistic
for the upcoming quarter modifies outlook