Which type of sorting algorithm starts at the first position and moves the pointer until the end of the list, determining the lowest value?

What is the time complexity of a quicksort algorithm? 

What is the built-in data structure that implements a hash table in Python? 

The np_2d array stores information about multiple family members. Each row represents a different person, and the columns store family member attributes in the following order:Age (years)Weight (pounds)Height (inches)How is the weight of all family members selected from the np_2d array?  

What Python code would return the value 2 from np_2d, where np_2d = np.array([[1, 2, 3, 4], [10, 20, 30, 40]])?