The correct answer is
C. Light can pass through Object B faster than it can pass through Object A.
In fact, the index of refraction of a material is defined as:

where c is the speed of light in vacuum and v is the speed of light in the material. Rearranging the equation, we can write the speed of light in the material as:

So we that, the smaller the refractive index n, the greater the speed of light in the material, v. In this problem, object B has lower refractive index than object A, so light travels faster in object B.
Answer:
The time taken by the duck to cross the lake is, t= 4 s
Explanation:
Given data,
The initial speed of the ducks, u = 3 m/s
The final speed of the ducks, v = 7 m/s
The acceleration of the duck, a = 1 m/s²
The formula for the acceleration is,
a = (v - u) / t
∴ t = (v - u) / a
Substituting the given values in the above equation,
t = (7 - 3) / 1
= 4 s
Hence, the time taken by the duck to cross the lake is, t= 4 s
The first one is the light bends sheikh is known as refraction
The forces of gravity between two objects are smaller when the objects are farther apart.