While writing a DataFrame onto a CSV file, which argument would you use in to_csv() for NaN values' representation as NULL ?

1. NaN = NULL
2. na_rep = NULL
3. na_value = NULL
4. na = NULL

Which of the following libraries let you establish a connection with a MySQL database from within Python ?

1. mysql.connector
2. Pymysql, sqlalchemy
3. pandas
4. numpy

In pandas.read_sql(<A>, <B>), <B> is

1. connection name
2. table name
3. SQL query string
4. database name

To suppress the creation of a column for index labels of a DataFrame, …………… argument is specified in to_sql().

1. if_exists = False
2. index = False
3. index = True
4. if_exists = True