A student predicts that a block sliding down a ramp inclined at $45$ degrees should have an acceleration of approximately $\backslash (7\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}^\{2\}\backslash ).$ The block is released from rest, and the student measures the distance the block travels and the time it takes to travel that distance. The student determines that the block's acceleration is only $\backslash (5\mathrm{.}5\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}^\{2\}\backslash ).$ Which of the following is the most likely reason for the difference between the predicted and calculated accelerations?

The student's model used to make the prediction did not account for the mass of the block.

The student's model used to make the prediction did not account for all of the forces that are exerted on the block.

The student's experimental procedure did not measure the correct quantities needed to calculate the acceleration.

The student's experimental procedure did not use enough trials to accurately determine the block's acceleration.