A patient reports horizontal double vision. When a red glass is placed over her right eye and she is asked to look at a flashlight off to her left, she reports seeing a white light and a red light. The red light appears to her to be more to the left than the white light. Her right pupil is more dilated than her left pupil and responds less briskly to a bright light directed at it than does the left pupil. The injury likely to be responsible for all of these observations is one involving which of the following nerves?

a. The second cranial nerve

b. The third cranial nerve

c. The fourth cranial nerve

d. The sixth cranial nerve

e. None of the above