phrase usage - "Kristina 'has passed'/'passed' her exam! She 'has got'/'got' 90%"

1. 
   

   Kristina has passed her exam!

   
   


2. 
   

   Kristina passed her exam!

   
   

Does English use the present perfect (1) or the past tense (2) to announce news?

Apart the way to express the vote—90%, 90, I don't know—which of the following sentences is more natural to give further details?

a. She has got 90%.

b. She got 90%.