Correct Answer - C
`(a+b-c)^(2)+(b+c-a)^(2)+(c+a-b)^(2)=?`
`impliesa+b+c=0` (given)
`implies a+b=-c`
`implies b+c=-a`
`implies a+c=-b`
`implies (a+b-c)^(2)+(b+c-a)^(2)+`
`(c+a-b)^(2)`
`implies(-c-c)^(2)+(-a-a)^(2)+(-b-b)^(2)`
`implies (-2c)^(2)+(-2a)^(2)+(-2b)^(2)`
`implies 4c^(2)+4a^(2)+4b^(2)`
`implies 4a^(2)+b^(2)+c^(2)`
