A) The energy of the log will remain the same. The position of the log will remain the same left to right, but it will move up and down.
When waves pass through the water, they transmit energy through the water. When these waves reach the log, they will cause the log to bob up and down, but they won't push the log to the side unless the wave is significantly large or powerful.
The energy of the log does not increase because the energy is not stored in the log; it is merely transferred through the log and then continues on past it. The log returns to its original energy state once the wave has passed.