University of Phoenix Project Forecasting Techniques Paper

I’m working on a management multi-part question and need an explanation and answer to help me learn.

By now, you have been exposed to different abbreviations such as BAC, ETC, and EAC in Earned Value Management. Are the budget at completion (BAC) and the estimate at completion (EAC) the same thing? From the four choices, 

At the project start, budget at completion equals estimate at completion – but that can change.

Estimate at completion and estimate to complete are the same thing.

Each organization designs its own terms to describe what a project will cost.

1. All projects vary, so after you budget costs, estimate your accuracy with ETC.