" (a) Who read the letter? "

A student sitting on the last bench can read the letters written on the blackboard but is not able to read the latters written in his text book. Which of the following statements is correct?

Assuming that a person of normal sight can read print at such a distance that the letters subtend an angle of 5' at his eye. Find what is the height of the letters that he can read at a distance of 756 meteres ?