Answer
a) less than
b) II
Work Step by Step
(a) It is given that pie 1 is hotter than pie 2. This means that pie 1 has more energy than pie 2 and it is more massive than pie 2. Thus, when same forces are applied to the two pies, the massive pie that is pie 1 will have less acceleration.
(b) We know that the best explanation is option (II) -- that is, the fact that pie 1 is hot means that it behaves as if it has more mass than pie 2, and therefore it has a smaller acceleration.
