Final answer:
The sentence fragment in the given options is B. According to many experts on Alaska.
Step-by-step explanation:
The sentence fragment in the given options is B. According to many experts on Alaska.
A sentence fragment is an incomplete sentence that lacks a subject, a verb, or both. In option B, 'According to many experts on Alaska' is a dependent clause that starts with a preposition but doesn't have a main clause to complete the sentence. Therefore, it is a sentence fragment.