A singly reinforced beam has breadth b, effective depth d, depth of neutral axis n and critical neutral axis n1. If fc and ft are permissible compressive and tensile stresses, the moment to resistance of the beam, is

• A. <img src="/_files/images/civil-engineering/rcc-structures-design/69-13-6-1.png">
• B. <img src="/_files/images/civil-engineering/rcc-structures-design/69-13-6-2.png">
• C. <img src="/_files/images/civil-engineering/rcc-structures-design/69-13-6-3.png">
• D. all the above