Which of the Following Techniques Was Not Used by Hubel

Multiple Choice

Which of the following techniques was not used by Hubel and Wiesel to study the role of visual experience in the development of the visual system?

A) Suturing closed the lids of one or both eyes during infancy
B) Allowing light to enter the eye, but blurring vision (e.g. by a translucent lens) during infancy
C) Producing an artificial squint
D) Rearing kittens in the presence of a single wavelength of light
E) All of the above were used by Hubel and Wiesel.