a=[13,56,17]
a.append([87])
a.extend([45,67])
print(a)

a=[13,56,17]
a.append([87])
a.extend([45,67])
print(a)

A. [13, 56, 17, [87], 45, 67]
B. [13, 56, 17, 87, 45, 67]
C. [13, 56, 17, 87,[ 45, 67]]
D. [13, 56, 17, [87], [45, 67]]

Solution

A. [13, 56, 17, [87], 45, 67]

Explanation

The append function simply adds its arguments to the list as it is while extend function extends its arguments and later appends it.