While interviewing Joe, Dr. Willard discovers that Joe has a genetic predisposition for schizophrenia because his uncle and mother had schizophrenia. Dr. Willard also believes the fact that Joe was homeless for several months after being expelled from school and "disowned" by his parents triggered his schizophrenia. Dr. Willard probably follows the model of psychological disorders

A). Diathesis-stress.

Explanation:

'Diathesis-stress' model is demonstrated as the theory which asserts that the mental disorders are a product of either genetic predisposition or biological proneness for the disorder amalgamated with stressful conditions that play an advanced role in facilitating the disorder.

As per the given description, Willard more likely follows the 'diathesis-stress' model of psychological disorders as he considers Joe's 'genetic predisposition'(for schizophrenia which he inherited from his mother or uncle) combined with the stressful situations(remain homeless, being expelled from the school, disowned by his parents, etc.) together contributed to triggering the same disorder 'schizophrenia' in him. Thus, option A is the correct answer.

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals