Tests conducted on given samples for finding the vibration induced in them

Question

1. There are four samples P, Q, R and S with natural frequencies 64, 96, 128 and 256 Hz, respectively. They are mounted on test setups for conducting vibration experiments. If  loud pure note of frequency 144Hz is produced by some instrument, which of the samples will show the most perceptible induced vibration?               

(a) P                                (b) Q                            (c) R                               (d) S