The correct answer is C. Rs. 7,500.
Goodwill is an intangible asset that represents the value of a company’s reputation, customer base, and other factors that make it more valuable than the sum of its assets. When a new partner is admitted to a firm, the goodwill is usually revalued to reflect the new partner’s share of the business. In this case, the goodwill is valued at Rs. 30,000, and C is admitted for a $\frac{1}{4}$ share. This means that C is entitled to a $\frac{1}{4}$ share of the goodwill, or Rs. 7,500.
Option A is incorrect because it is the value of the goodwill as it appears in the books. This is not the amount that C is supposed to bring.
Option B is incorrect because it is the amount of goodwill that would be brought in if C were admitted for a $\frac{1}{2}$ share.
Option D is incorrect because it is the total value of the goodwill. This is not the amount that C is supposed to bring.