The universal task of the education is to teach the children read, write and learn mathematics. If they are having intelligence but face difficulty in these tasks then these are suffering with the specific learning disorders.
This is defined as the difficulty in learning and using academic skills below the chronological age. This is due to the inability of several brain areas to work together.
Impairment in reading is called the dyslexia and impairment in mathematics is called the dyscalculia. These two are less common than writing.
Hence the options a and b are not correct.
Impairment in written expression is called the dysgraphia that is more common than the sloppy handwriting.
Hence the correct option is .