as immigrants or as an immigrant?

[partitabach]

The respondents of this survey said that their greatest challenge as immigrants living in America was the language barrier.

from the following sentence above, is the pluralized noun "as immigrants" gramatically correct?
inst it supposed to be written as "as an immigrant"?



ps.

in previous time
Arkin was actually the person who caused of the accident

from the sentence above, why did they attach of in the sentence?
whats the difference between who caused the accident and who caused of the accident?

[Alan]

Yes, the plural 'immigrants' is correct since it refers back to a plural subject (they).