Which of the following is the largest aperture opening

a) f/1.7
b) f/2.8
c) f/4
d) f/8
e) f/16

is the correct answer.

Explanation:

The term Aperture is referred for the unlatched area inside the  lens of camera which is  also termed as lens Diaphragm. When an exposure is done, the aperture unlatched area or say it diaphragm size regulates itself so that the amount of light passes through it while the opening time of shutter curtain.

Aperture size in a camera can be  fixed or adjustable so that it could be changed accordingly as needed. This size is normally calculated in f-numbers or it may sometimes called f-stops.

From the given options, f/1.7 is the largest aperture size.