Concept:In SHM, the maximum velocity is given by vmax​=aω, where a is the amplitude and ω=mK​​ is the angular frequency.Explanation:For particle A, the maximum velocity is vmax,A​=aA​mKA​​​.For particle B, the maximum velocity is vmax,B​=aB​mKB​​​.Since the maximum velocities are equal, we equate them:aA​mKA​​​=aB​mKB​​​.The masses are equal, so m cancels out:aA​KA​​=aB​KB​​.Rearranging to find the ratio of the amplitude of B to that of A:aA​aB​​=KB​KA​​​.Thus, aB​:aA​=KA​​:KB​​.Answer:The ratio of the amplitude of B to that of A is KA​​:KB​​, so the correct option is B.