Critical Reasoning

Beverage company representative: The plastic rings
that hold six-packs of beverage cans together
pose a threat to wild animals, which often
become entangled in the discarded rings and
suffocate as a result. Following our lead, all
beverage companies will soon use only those
rings consisting of a new plastic that
disintegrates after only three days' exposure to
sunlight. Once we all complete the switchover
from the old to the new plastic rings, therefore,
the threat of suffocation that plastic rings pose
to wild animals will be eliminated.
Which one of the following, if true, most seriously
weakens the representative's argument?
(A) The switchover to the new plastic rings will
take at least two more years to complete.
(B) After the beverage companies have switched
over to the new plastic rings, a substantial
number of the old plastic rings will persist
in most aquatic and woodland environments.
(C) The new plastic rings are slightly less
expensive than the old rings.
(D) The new plastic rings rarely disintegrate
during shipping of beverage six-packs
because most trucks that transport canned
beverages protect their cargo from sunlight.
(E) The new plastic rings disintegrate into
substances that are harmful to aquatic
animals when ingested in substantial
quantities by them



I didn't get why option E is wrong.


E says - disintegrate into substances that are harmful

Argument conclusion says- the threat of suffocation

if something is harmful that includes suffocation as well!

I feel harmful has much broader scope but then the argument says about WILD ANIMALS and the correct choice talks about aquatic and woodland environments then that also has scope problem.

Please help!