The total radiation pattern of a two element array, elements separated by a distance λ/4 and phase difference \(\frac{π}{2},\) the nulls occur at (for far field) ____________

• A. 0, ±π/2
• B. π, ±π/2
• C. π, ±π/4
• D. ____________a) 0, ±π/2b) π, ±π/2c) π, ±π/4d) π/4, ±π/2