图示拉杆为线性材料，横截面面积相等.在荷载作用下产生的位移最大的为()。

• A.<img src="https://timg.fentiku.com/img/2018-04-09/5acadbc413efb.png" alt="" />
• B.<img src="https://timg.fentiku.com/img/2018-04-09/5acadbc43274a.png" alt="" />
• C.<img src="https://timg.fentiku.com/img/2018-04-09/5acadbc456972.png" alt="" />
• D.<img src="https://timg.fentiku.com/img/2018-04-09/5acadbc47654a.png" alt="" />

正确答案：D