Find out whether there is any grammatical error in below sentence.
Mahatma Gandhi did not solve / all the problems of the future / but he did solve / problems of his own age.
A. Mahatma Gandhi did not solve
B. all the problems of the future
C. but he did solve
D. problems of his own age
E. No error
Answer: Option B

Option D should be the answer. Before problems it should be "the".