After nonzero transformation k to polygon P has been performed four consecutive times, polygon P has returned to its original position in the plane. Which of the following could not describe transformation k? A) a reflection over a fixed line
B) a rotation by 90 degrees about a fixed point
C) a rotation by 180 degrees about a fixed point
D) a translation by (a, b) units in the plane

Answer this question, only if you know the answer. 30 points and brainliest!

Find the slope of the line below . enter your answer as a fraction or decimal. use a slash mark ( / ) as the fraction bar if necessary

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.