The Line Integral $\int$ C $( x + y ) d s$

Multiple Choice

The line integral $\int$ C $( x + y ) d s$ , where C is the curve $x = t , y = 1 - t , 0 \leq t \leq 1 ,$ is

A) $2 \sqrt { 2 }$
B) $\sqrt { 2 }$
C) $3 \sqrt { 2 }$
D) $\sqrt { 3 }$
E) $\frac { 1 } { \sqrt { 2 } }$