1) x+z = 2u^2
x- z = - 2v^2
(x+z)(x-z)= x^2 - z^2 = -4(uv)^2
[(x^2 - z^2)/ y^2 ] = (2uv)^2 / -4(uv)^2 -------- z^2 = x^2 + y^2
z = +- ( 11^2 + 60^2 ) but as z = u^2 + v^2 so z is positive
so 1 is sufficient

2) x+z = 2u^2
2 is sufficient
so D is correct answer