The West Indian manatee, a distant relative of the elephant, returned

The West Indian manatee, a distant relative of the elephant, returned to the sea some 50 million years ago. These thousand-pound herbivores inhabit the warm coastal waters where Americans like to play. Despite conservation efforts, criminal penalties for harming these creatures, and an overabundance of SAVE THE MANATEE! bumper stickers, none of these animals can be considered safe.

Which of the following, if true, most strongly supports the argument above?

A) Last year, several manatees were mysteriously killed by an unidentified toxin.
B) All manatees swim at depths that make them vulnerable to the blades of motorboat engines.
C) Most tourists are unaware of the ongoing efforts to save the manatee.
D) The population of manatees in the wild has dwindled to fewer than 2,500 animals.
E) Although dozens of manatee deaths are documented each year, many more deaths go unreported.

B it is

Criminal Penalties,Conservation efforts,SAVE them stickers...Although Enough is being done through awareness, the animals are still not safe.So something not to do with lack of awareness etc.

A- Just because of a separate incidence you cannot conclude that they are unsafe.We cannot say that this will occur again & hence the Manatees are unsafe...Rejected
B- Lives Near Coastal Water where US ppl play--> Swim at boat level--> Although people aware they harm them unconsciously--> Can be a probable answer
C- Tourists are unaware.But how does it matter.Nothing about them hurting the manatees or about tourists frequently visiting the coasts is mentioned in the argument...Rejected
D- Number- Irrelevant-What if there are 100000000 manatees..Rejected
E- Deaths go unreported- We don't know the cause of the death- Is it natural or man made- Rejected