The number of construction takes singular :

The number of students is .....

A number of construction takes plural

A number of students are .....

prat_agl wrote:The number of construction takes singular :

The number of students is .....

A number of construction takes plural

A number of students are .....

"The number of men THAT are..."
i think "that" modifies "men" and the plural form is correct.

Hi,

I actually find both the options weird but if I have to pick one, then I will pick A

My analysis:

A) I think use of plural "are" is correct because it is correctly referring to "men" and not "number" but here I would rather use "who" instead of "that", since who is used to describe people. Secondly, I would use "greater" or simply "more" than "higher".

So, correct sentence should read: The number of men who are legally married but harboring concubines outside their matrimonial homes may be greater/ more than twice the population previously imagined.

B) This is clearly wrong for me because of comparison sake- here Men is compared with the population and that doesn't make sense. Also the prepositional phrase - married outside but harboring concubines outside their matrimonial homes distorts the intent of original sentence.