I am having trouble with the following sentence:
"The complexity and diversity of the new platforms is worrying us."
If "complexity" and "diversity" constitute two subjects, then the verb should presumably be "are"; however, the sentence feels more natural with "is". Is this correct? Is there a linguistic term for this occurrence?
The following questions address the general topic of compound subjects, but not specific cases like this:
And the following question seems to have somewhat inconclusive answers:
So this question is not really a duplicate of these three.