a.) is the correct answer.
the answer is b ) square root of 5
the total distance that martina travels that day is
(distance from home to mom's office) plus (distance from mom's office to school)
plus (distance from school to library) plus (distance from library to friend's house)
plus (distance from friend's house to martina's house).
(we don't know what any of these distance actually is.)
energy in a material....