If two tensile forces mutually perpendicular act on a rectangular parallelopiped bar are equal, the resulting elongation of the pipe, is

• A. <img src="/_files/images/civil-engineering/strength-of-materials/125-6.39-1.png">
• B. <img src="/_files/images/civil-engineering/strength-of-materials/125-6.39-2.png">
• C. <img src="/_files/images/civil-engineering/strength-of-materials/125-6.39-3.png">
• D. <img src="/_files/images/civil-engineering/strength-of-materials/125-6.39-4.png">
• E. <img src="/_files/images/civil-engineering/strength-of-materials/125-6.39-5.png">