Which one of the following optical elements can change the wavefront of a plane wave into a spherical wavefront?

Correct option is A

Correct answer is A
Explanation:
A plane wavefront can be transformed into a spherical wavefront by optical elements that focus or diverge light. This is achieved by elements that introduce curvature to the wavefront.
· A plane convex lens focuses parallel rays to a point and converts a plane wavefront into a spherical one.
· A concave mirror also introduces curvature but reflects light instead of refracting it.
· Prisms only deflect light without altering the wavefront's nature.
· A plane mirror reflects light without changing the wavefront's shape.