Exam Certified Platform Developer II topic 1 question 48 discussion

Example 1:
AggregateResult[] groupedResults = [SELECT CampaignId, AVG(Amount) FROM Opportunity GROUP BY CampaignId]; for (AggregateResult ar : groupedResults)
{
System.debug('Campaign ID' + ar.get('CampaignId'));
System.debug('Average amount' + ar.get('expr0'));
}
Example 2:
AggregateResult[] groupedResults = [SELECT CampaignId, AVG(Amount) theAverage FROM Opportunity GROUP BY CampaignId]; for (AggregateResult ar : groupedResults)
{
System.debug('Campaign ID' + ar.get('CampaignId'));
System.debug('Average amount' + ar.get('theAverage'));
}
Example 3:
AggregateResult[] groupedResults = [SELECT CampaignId, AVG(Amount) FROM Opportunity GROUP BY CampaignId]; for (AggregateResult ar : groupedResults)
{
System.debug('Campaign ID' + ar.get('CampaignId'));
System.debug('Average amount' + ar.get.AVG());
}
Example 4:
AggregateResult[] groupedResults = [SELECT CampaignId, AVG(Amount) theAverage FROM Opportunity GROUP BY CampaignId]; for (AggregateResult ar : groupedResults)
{
System.debug('Campaign ID' + ar.get('CampaignId'));
System.debug ('Average amount' + ar.theAverage);
}
Which two of the examples above have correct System.debug statements? (Choose two.)