In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Q: Problem: the product of the squares of two positive integers is 9 . how many pairs of positive integers satisfy this condition ? 
Options: a ) 0 , b ) 1 , c ) 2 , d ) 3 , e ) 4

A: b
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Q: Problem: find the area of a rhombus one side of which measures 20 cm and one diagonal is 28 cm . 
Options: ['a ) 200 cm 2', 'b ) 300 cm 2', 'c ) 400 cm 2', 'd ) 448 cm 2', 'e ) 100 cm 2']

A: d
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Q: Problem: on the xy - coordinate plane , point a lies on the y - axis and point b lies on the x - axis . points a , b , and c form a right triangle with a 90 - degree angle at point c and the triangle has an area of 20 . if ac is parallel to the x - axis , and bc is parallel to the y - axis , which of the following could be the coordinates of point c ? 
Options: ['a ) ( 8 , - 3 )', 'b ) ( 4 , 5 )', 'c ) ( - 5 , 7 )', 'd ) ( - 2 , - 20 )', 'e ) ( - 15 , - 3 )']

A:
d
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