Answer:
The correct answer is D. The campaign to protect toads has been in existence for over five years and yet the toad population continues to decline.
Step-by-step explanation:
For any successful campaign of conservation, the involvement and participation of local people is necessary because local people play an important role in the conservation of any species found in the habitat where they live.
Therefore when people are not enthusiastic about any conservation program then it can result in the failure of that program. So, in this case, it can be seen that people are unenthusiastic about saving toads, therefore, this campaign will have a problem in saving toads.
Therefore, the campaign to protect toads has been in existence for over five years and yet the toad population continues to decline would be the most strengthened opinion by experts.