If d is the clear depth of a plate girder, t is the minimum required thickness of the web, C is the maximum clear distance between vertical stiffeners, the moment of inertia of a pair of stiffeners about the centre line of the web, is

• A. <img src="/_files/images/civil-engineering/steel-structure-design/106-14-169-1.png">
• B. <img src="/_files/images/civil-engineering/steel-structure-design/106-14-169-2.png">
• C. <img src="/_files/images/civil-engineering/steel-structure-design/106-14-169-3.png">
• D. <img src="/_files/images/civil-engineering/steel-structure-design/106-14-169-4.png">