A mango tree is at the bank of a river and one of the branch of tree extends over the river. A tortoise lives in the river. A mango falls just ono the tortoise. The acceleration of the mango falling from tree as it appears to the tortoise is (refractive index of water is `4//3` and the tortoise is stationary)
A. g
B. `3g//4`
C. `4g//3`
D. none of these