An object X is placed in air in front of a convex refracting surface. Following four sketches are drawn for depicting the situation (symbols carry their usual meanings).

Which of these could be correct sketches?
a)

b) 

c)

d)

Correct option is C

Correct answer is C
Analyzing the sketches:
· Sketch a) correctly illustrates the convex refracting surface forming an appropriate image of object X.
· refractive index of material must be greater than air.