The new profit-sharing ratio of A, B and C will be if A and B share profits in the ratio 4:3 and C is admitted for 1/8 share?

Correct option is A

Old ratio A : B = 4 : 3. C’s share = 1/8. Remaining share = 1 – 1/8 = 7/8.
A’s new share = (7/8) × (4/7) = 4/8 = 1/2. B’s new share = (7/8) × (3/7) = 3/8. C’s share = 1/8.
Multiply all by 8: A : B : C = 4 : 3 : 1.
That matches option (a).