Premise 1: Lofgren's is rare in chickens than it is in cattle.
Premise 2: Both cattle and chickens eat the same food that may cause disease.
Premise 3: It takes one year for symptoms to appear.
Premise 4: Chickens are brought to market in their first year.

Now the question asks for inference NOT the conclusion.
What we can infer?

It takes 1 year for symptoms to year doesn't mean that the disease can not be detected in the first year. The only thing we can infer is NO symptoms can appear before

1 year and if symptoms are there then the chicken is at least one year old.

2. The rarity of disease is not related to food. There MUST be some other cause of rarity.

3. No symptoms of the disease have been observed in chickens brought to the market.

Answer: C