After adopting broadband internet access, wireless personal

The correct answer is (B) "doubling to 250 the number of junior staff members in the claims department." This sentence is describing the increase in the number of junior staff members in the claims department, and the most concise and grammatically correct way to express this is by using the gerund form "doubling." Option (A) and (C) are incorrect because they use the phrase "the junior staff" instead of "the number of junior staff members," which changes the meaning of the sentence. Option (D) is incorrect because it uses the phrase "junior staff members of the claims department," which is redundant. Option (E) is incorrect because it adds the unnecessary qualifier "that" at the end of the sentence.