Python slicing and calculating maximum

My questions are related to the lesson that introduces NumPy Analyzing Patient Data.

Question 1:

You have a 1D array a:

a = numpy.array([2,4,6,8,10,12]) 
print a

produces:

array([ 2,  4,  6,  8, 10, 12])

How can you select the last three elements, i.e., 8, 10, 12?

1. a[4:]

2. a[4:8]

3. a[3:]

4. a[3,4,5]

Question 2:

You have a 2D array b:

b = numpy.array([[1,2,3,4],[5,6,7,8]])
print b

produces:

array([[1, 2, 3, 4],
       [5, 6, 7, 8]])

How can you check the maximum value in the second and last row?

1. b[1].max()

2. b[:,1].max()

3. b[1,:].max()

4. b.max()[1]

Discussion of the answers and possible misconceptions:

1. OK - demonstrates a possible shorter notation, i.e., b[1] is the same as b[1,:]

2. wrong - one can confuse the C/F order

3. OK

4. wrong - default behavior for array.max() is calculating one value for all array