In a doubly-reinforced beam if c and t are stresses in concrete and tension reinforcement, d is the effective depth and n is depth of critical neutral axis n, the following relationship holds good

• A. <img src="/_files/images/civil-engineering/rcc-structures-design/70-13-14-1.png">
• B. <img src="/_files/images/civil-engineering/rcc-structures-design/70-13-14-2.png">
• C. <img src="/_files/images/civil-engineering/rcc-structures-design/70-13-14-3.png">
• D. <img src="/_files/images/civil-engineering/rcc-structures-design/70-13-14-4.png">
• E. <img src="/_files/images/civil-engineering/rcc-structures-design/70-13-14-5.png">