What is a 2D list ?

What is a nested list ?

What will be the output of the following Python code ?

a = [10,23,56,[78, 10]]
b = list(a)
a[3][0] += 17
print(b)

1. [10, 23, 71, [95, 10]]
2. [10, 23, 56, [78, 25]]
3. [10, 23, 56, [95, 10]]
4. [10, 34, 71, [78, 10]]

What will be the output of the following Python code ?

lst1 = "hello"
lst2 = list((x.upper(), len(x)) for x in lst1) 
print(lst2)

1. [('H', 1), ('E', 1), ('L',1), ('L',1), ('O', 1)]
2. [('HELLO', 5)]
3. [('H',5), ('E', 5), ('L',5), ('L',5), ('O', 5)]
4. Syntax error