Multi-choice problem: Continue writing the next sentence in this paragraph:

How to save a fading newborn puppy
Monitor the litter closely.
Look for abnormalities like pups without suckling instincts, excessive crying, and physical deformities such as flattened chests or any absent body parts. Seek emergency care as soon as possible if you suspect something's not right.

pick from the following.
[1]. A fading newborn puppy cannot raise its head and neck unhealthily. Likewise, a smiling puppy cannot sit or cross its legs.
[2]. Be ready to report your observations to the vet. Take an initial weight of each pup after birth.
[3]. Notice pauses in their suckling behavior. Timid mother kits are often deterred by unusually shy or aggressive puppies.
[4]. Keep a detailed record of your puppies' health. Consult a vet about proper care for your house's foster puppies, including vaccinations and illnesses.
[2].