Python data type - Strings & Applications

Question: 1

What is the output of the following program?
#!/usr/bin/python3
def slicing(str):
    S = str[:2]
    return S
if __name__ == '__main__':
    str = "bottleneck"
    Mr = slicing(str)
    print ("String is:",Mr)
String is: ck
String is: bottlene
String is: ttleneck
String is: bo