If a lens has a focal length of 25 cm, what will be the power of that lens?

Correct option is D

The correct answer is (d) 4 D.
The power of a lens (P) is given by the formula:
P=1f (in meters) in meters)
where f is the focal length in meters.
For a focal length of 25 cm:
f=0.25 m
P = =4diopters (D)