If z and \[\omega \]are two non-zero complex numbers such that \[\left| z \right|=\left| \omega \right|\]and arg z + arg \[\omega \]=\[\pi \], then z equals

• A. \[\bar{\omega }\]                      
• B. -\[\bar{\omega }\]
• C. \[\omega \]                   
• D. -\[\omega \]