ANSWER
[tex]\text{ b. None of the above}[/tex]
EXPLANATION
The buoyant force of the rock is the difference between the weights of the rock out of water and in water.
Hence, the buoyant force on the rock is:
[tex]\begin{gathered} F_B=5-3 \\ F_B=2N \end{gathered}[/tex]
Hence, the correct option is option b (None of the above).
