What is output for the given python code?
import numpy as np
import pandas as pd
arr = np.array([[ 'Balaji', 'Sam', 'Ram'],
['50k', '90k', '60k'],
[30, 25, 28]])
df_ = pd.DataFrame(arr, columns=['name', 'salary', 'age'])
print(df_.columns[1][2])
1
age
2
salary
3
a
4
l