The gerund phrases are:
- "Being the accounts manager" (Subject)
- "blowing bubbles to his little sister" (Subjet Complement)
Gerund phrases begin with a gerund or -ing word, and include other modifiers and objects. They function as nouns, and can be the subject, subject complement or direct object of the sentence.
The rest of the alternatives are not gerund phrases because options one and three possess an infinitive verb ("to bring" and "to win"), and "Hiking for two hours" is a present participle clause.
B seems to be the best option. Although D is also an interesting choice, I would go with B. "are a hazard for hatchlings" This does clarify the relationship between the claim that lights are hazardous for baby sea turtles and the reason that lights prevent them from coming ashore.
I hope this helps! :)
