Answer: The phrase that best completes the sentence provided is D. muchas especies estén en peligro de extinción.
Step-by-step explanation: "Es una lástima que" can be translated as "It is a pity that". In that way, what must follow this portion of the sentence is a phrase that describes a negative situation. The only option that presents a negative situation is D. "muchas especies estén en peligro de extinción", which means "many species are in danger of extinction". In contrast, all the other options present positive situations, which makes them unsuitable for the sentence provided.