If q–a = 1 /r and r–b = 1 /s and s

If q^–a = 1 /r and r^–b = 1 /s and s_{–c = 1 /q of abc is. the value of abc is _______ .}

q^-a =	1	⇒	1	=	1	⇒ q^a = r
	r		q^a		r

r^-b =	1	⇒	1	=	1	⇒ s = r^b
	q		r^c		s

r^-c =	1	⇒	1	=	1	⇒ s^c = q
	q		s^c		q

q^a=r⇒(s^c)^a =r⇒ s^ac = r
(s^ac)^b=s⇒s^abc=s¹
∴ abc = 1
∴ Option (c) is correct