Four point charges \[-Q,\,-q,\text{ }2q\] and \[2Q\] are placed, one at each comer of the square. The relation between Q and q for which the potential at the centre of the square is zero, is [AIPMT(S) 2012]

• A. \[Q=-q\]
• B. \[Q=-\frac{1}{q}\]
• C. \[Q=q\]
• D. \[Q=\frac{1}{q}\]