Three charges are placed at the vertices of an equilateral triangle of side ?a? as shown in the following figure. The force experienced by the charge placed at the vertex A in a direction normal to BC is [AIIMS 2003]

• A.            \[{{Q}^{2}}/(4\pi {{\varepsilon }_{0}}{{a}^{2}})\]
• B.            \[-{{Q}^{2}}/(4\pi {{\varepsilon }_{0}}{{a}^{2}})\]
• C.            Zero
• D.            \[{{Q}^{2}}/(2\pi {{\varepsilon }_{0}}{{a}^{2}})\]