The correct answer is: B. Some textbooks written by Prabhakar are published by publishers other than ABC Publishing Company.
We know that all the books written by Prabhakar are textbooks, and some of his books are published by ABC Publishing Company. This means that some of the textbooks written by Prabhakar are published by ABC Publishing Company, but not all of them. Therefore, some textbooks written by Prabhakar must be published by publishers other than ABC Publishing Company.
The other options are incorrect because they do not follow logically from the given information. Option A is incorrect because it states that ABC Publishing Company publishes textbooks only, but we know that Prabhakar has written some critical essays as well. Option C is incorrect because it states that ABC Publishing Company publishes some critical essays written by Prabhakar, but we know that not all of Prabhakar’s books are critical essays. Option D is incorrect because it states that all the books published by ABC Publishing Company have been written by Prabhakar, but we know that some of Prabhakar’s books are published by other publishers.