按弹性理论，四边支承板在满足下列( )项条件时应按双向板设计。

• A.l<img src="https://timg.fentiku.com/97/2016/12/22/ywLHEXnfC8.png" title='ywLHEXnfC8.png' alt='ywLHEXnfC8.png'/>／l<img src="https://timg.fentiku.com/97/2016/12/22/u643r8FPAM.png" title='u643r8FPAM.png' alt='u643r8FPAM.png'/>≥2
• B.l<img src="https://timg.fentiku.com/97/2016/12/22/L8zztXHnEG.png" title='L8zztXHnEG.png' alt='L8zztXHnEG.png'/>／l<img src="https://timg.fentiku.com/97/2016/12/22/swoLnUfQsw.png" title='swoLnUfQsw.png' alt='swoLnUfQsw.png'/>≤2
• C.l<img src="https://timg.fentiku.com/97/2016/12/22/ZF525FxRCr.png" title='ZF525FxRCr.png' alt='ZF525FxRCr.png'/>／l<img src="https://timg.fentiku.com/97/2016/12/22/bezJDxLRbc.png" title='bezJDxLRbc.png' alt='bezJDxLRbc.png'/>≥3
• D.l<img src="https://timg.fentiku.com/97/2016/12/22/mESZ1ZyA2b.png" title='mESZ1ZyA2b.png' alt='mESZ1ZyA2b.png'/>／l<img src="https://timg.fentiku.com/97/2016/12/22/qC2Ma3fYJq.png" title='qC2Ma3fYJq.png' alt='qC2Ma3fYJq.png'/>≤4

正确答案：B