The correct answer is: A. RPQS
The sentence is about the difficulty of tolerating faults in a boy of fourteen. The first part of the sentence, “It is easy to excuse the mischief of early childhood,” sets up the contrast between the relative ease of excusing the faults of a young child and the difficulty of excusing the faults of an older child. The second part of the sentence, “but it is hard to tolerate even unavoidable faults in a boy of fourteen,” provides the evidence for this contrast. The third part of the sentence, “in a boy of fourteen,” specifies the age group that is being discussed. The fourth part of the sentence, “the mischief of early childhood,” provides an example of a fault that is easy to excuse. The fifth part of the sentence, “to tolerate even unavoidable faults,” provides an example of a fault that is difficult to excuse.
The other options are incorrect because they do not follow the logical order of the sentence. Option B, QRSP, puts the evidence for the contrast before the contrast itself. Option C, QRPS, puts the example of a fault that is easy to excuse before the example of a fault that is difficult to excuse. Option D, RPSQ, puts the example of a fault that is difficult to excuse before the evidence for the contrast.