What is life about? How do you make sense of your existence? What is your best estimate / theory of what we are doing here and how all of this came to be?

Is this: (A) Christianity - God created the world and man rebelled? (B) Evolution - Happenstance? (C) Other alien races exist and are in a 10000 year battle; and we are in a living in Reptilian Soul Recycler? (D) Simulation - Some type of computer simulation running for purposes beyond our comprehension.... (E) ....

I'm really curious to hear of your best estimate / theory of how all of this came to be.