You have the following code that prepares an experiment to run a script:

from azureml.core import Experiment, ScriptRunConfig

script_config = ScriptRunConfig(source_directory='./script',
                                script='train.py',
                                compute_target='local')

The experiment must be run on the local computer using the default environment. You need to add code to start the experiment and run the script. Which code segment should you use?