gaokao 2018 Q2

gaokao · China · national-I-arts 5 marks Complex Numbers Arithmetic Modulus Computation
Let $z = \frac { 1 - \mathrm { i } } { 1 + \mathrm { i } } + 2 \mathrm { i }$, then $| z | =$
A. 0
B. $\frac { 1 } { 2 }$
C. 1
D. $\sqrt { 2 }$
Let $z = \frac { 1 - \mathrm { i } } { 1 + \mathrm { i } } + 2 \mathrm { i }$, then $| z | =$

A. 0\\
B. $\frac { 1 } { 2 }$\\
C. 1\\
D. $\sqrt { 2 }$