Consider the following pairs of solution which will be isotonic at the same temperature. The number of pairs of solution…

Consider the following pairs of solution which will be isotonic at the same temperature. The number of pairs of solutions is/are
(a) \(1 M\) aq. \(NaCl\) and \(2 M\) aq. Urea
(b) \(1 M\) aq. \(CaCl _2\) and \(1.5 M\) aq. \(KCl\)
(c) \(1.5 M\) aq. \(AlCl _3\) and \(2 M\) aq. \(Na _2 SO _4\)
(d) \(2.5 M\) aq. \(KCl\) and \(1 M\) aq. \(Al _2\left( SO _4\right)_3\)

[JEE Main 2023, 6 Apr (Shift 2)]