Answer: d. helps to hold the lens and retina in place.
Step-by-step explanation:
The vitreous humor is a clear and colorless fluid which helps in filling up the space between the lens and retina of the human eye.
The composition of the vitreous humor consists of 99% of water, rest composition includes the proteins, sugars and salts. It has a jelly like appearance. The vitreous humor remains in contact with the retina. The pressure created by the vitreous humor keeps the retina and lens at it's place.
Thus option d is correct.