The maximum total settlement for raft foundation on clayey soils should be limited to A. 25 mm B. 25 to 40 mm C. 40 to 65 mm D. 65 to 100 mm

The correct answer is A. 25 mm.

The maximum total settlement for raft foundation on clayey soils should be limited to 25 mm. This is because clayey soils are relatively incompressible, and large settlements can cause damage to structures. In addition, large settlements can also lead to differential settlements, which can cause cracking in structures.

Option B is incorrect because it is too high. Option C is incorrect because it is too low. Option D is incorrect because it is not a valid option.