A32-year-old father of two small children lived in the midwestern united states. an avid hunter since childhood, the man visited annually with family and friends in colorado for elk hunting. his job required frequent travel to europe, where he enjoyed exotic foods. in 1988, his wife recalls, he began having problems. frequently he forgot to pick up things from the store or even that his wife had called him. later that year, he was unable to complete paperwork at his business and had difficulty performing even basic math. in england on business, he had forgotten his home phone number in the united states and couldn't remember how to spell his name for directory assistance. by september, his wife insisted he seek medical care. all the standard blood tests came back normal. a psychologist diagnosed depression, but a brain scan revealed spongiform changes. he was given six weeks to live because there is no treatment for this disease.

The question is incomplete and is missing the last part which I write below before the answer;

What is the most likely etiology (cause) of this disease?

The answer is "Prion".

The reason for the Transmissible spongiform encephalopathies is at present obscure, yet the maladies are known to be related with Prions. Weather Prions cause TSEs or are the consequence of contamination with another operator, for example, a virus which involves a debate by a minority of researchers. Prion maladies in a wide number of animal types are related with spongiform changes in cerebrum tissue.

This case has something to do with the answers stated below:

Prion

Prion diseases in a wide number of species are associated with spongy form changes in brain tissue

The answers above are most likely the etiology or the cause of this disease.

experiments.

surveys.

questionnaires.

interviews.

case studies.

participant and non-participant observation.

observational trials.

studies using the delphi method.

explanation:

i believe the primary and secondary sectors