Which API cannot be used to create the data model?
a. Ajax Toolkit for Force.com
b. Force.com API
c. Force.com single sign on API
d. Force.com MetaData API

Please let me know the answer with explanation .  Thanks in advance 

What tools you need to use to migrate Metadata to Two Different Production Orgs? (Choose 3)
a. Force.com IDE
b. Force.com Migration Tool
c. Change Set
d. Unmanaged Package
e. Data Loader

Please help me choose the right option with explanation.  When i answered this question in the website it says changeset is not one of the option.  Is that right?

Based on only the code below, what do we know about the data model?
interviewer__r.position__r.status__c = 'Open';
a. Position__r is a custom object.                       
b. Position__c is a custom field on the interviewer__c object
c. Status__c is a picklist field.                       
d. Interviewer__c is a custom object

Please let me know which is the right answer with explanation