The correct statement about the first transgenic cow "Rosie" is:

"All of these."

Rosie, the first transgenic cow, was genetically engineered to produce milk enriched with human alpha-lactalbumin, a protein found in human breast milk. This modification aimed to make the milk more nutritionally balanced for human babies. Rosie's milk contained approximately 2.4 grams of human alpha-lactalbumin per liter, providing a more balanced product for potential use in infant formula.

So, the correct option is "All of these," as it encompasses the protein-enriched milk, the presence of human alpha-lactalbumin, and the goal of creating a more balanced product for human babies.