9 (3.09) The function in numpy that can calculate the standard deviation is ( ) A. std() B. sd() C var() D ptp()

The correct answer is A. std(). The numpy function that can calculate the standard deviation is std(). The std() function in numpy computes the standard deviation along the specified axis. It takes the input array and returns the standard deviation of the values. The other options, sd(), var(), and ptp(), are not the correct functions for calculating the standard deviation in numpy.