My father was a hard working man but didn't earn much money.

A. Correctly punctuated

B. Add a comma after hard

C. Close up hard working

D. Add a hyphen after hard

A

D is not correct

It is correct to say either "He is a hard worker" or "He is hard-working," but it is incorrect to say "He is a hard working."

My choice is c

confirmed C

A. Correctly punctuated

Both c and d are correct, but I prefer d.

d should be correct from my research but there are dictionaries with hardworking as one word i guess go with the simplest answer which is close the words into one adjective...since i assume the posters are taking a test go its sad your teachers put a question that is disputed without telling you which one they want..

i'd go with D. It's a compound word, serving as one adjective.