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: 6 points lie on the circumference of a ellipse . what is the positive difference between the number of triangles and the number of quadrilaterals that can be created by connecting these points ? 
Options: a ) 4 , b ) 6 , c ) 5 , d ) 15 , e ) 20

A: c
****
Q: Problem: the area of a parallelogram is 72 sq m and its altitude is twice the corresponding base . then the length of the base is ? 
Options: a ) 6 , b ) 16 , c ) 8 , d ) 36 , e ) none

A: a
****
Q: Problem: find the area of the square , one of whose diagonals is 3.8 m long ? 
Options: ['a ) 7.22 m ^ 2', 'b ) 3.86 m ^ 2', 'c ) 8.96 m ^ 2', 'd ) 2.68 m ^ 2', 'e ) 7.89 m ^ 2']

A:
a
****