If x = 2 and y = - 3 is a unique solution of any pair of equation, then these values must satisfy that pair of equations.

Putting the values in the equations for every option and checking it -

From option (b).

LHS = 2x + 5y = 2(2+(- 3) = 4 + (- 15) = - 11 = RHS

and

LHS = 4x + 10y = 4(2) +10(- 3) = 8 + (- 30) = - 22 = RHS

It satisfies the pair of linear equation and hence is the unique solution for the equation.