The correct answer is B. Having read your letter, my German shepherd will stay inside after dark.
Step-by-step explanation:
In grammar, a dangling modifier is a grammatical mistake on the construction of sentences that occurs when a modifier, which is usually a word or words that act as an adjective or adverb and describe a noun, is not linked to the noun it describes and therefore the modifier dangles or in most cases is incorrectly associated with another noun. This often leads to confusing or ambiguous sentences. From the options provided the one that contains a dangling modifier is "Having read your letter, my German shepherd will stay inside after dark" because in this sentence the words "Having read your letter" act as a modifier, but the noun it modifies which is the person that read the letter has not been included which makes the modifier been associated with "my German shepherd", this does not make sense and is incorrect because a dog cannot read a letter, which means the modifier of the sentence dangles or remains without the noun it modifies and therefore the sentence contains a dangling modifier.