What is the major key that contains 3 sharps?

The major key that contains three sharps is indeed D Major. This key signature includes F#, C#, and G#.

In the context of the question, understanding the arrangement of sharps in major keys is essential. The order in which sharps are added in major keys is significant. When moving up in the circle of fifths, each new key adds a sharp. Starting from C Major, which has no sharps, the first sharp introduced is F# for G Major, followed by C# for D Major, and then G# for A Major.

A Major, the key associated with the answer, actually contains three sharps: F#, C#, and G#. This corresponds with the correct counting of sharps.

E Major, containing four sharps (F#, C#, G#, D#), and G Major with one sharp (F#), do not fit the criterion of having three sharps.

In summary, A Major's key signature matches the requirement of having three sharps, illustrating the importance of learning key signatures in relation to their sharps and flats, helping identify different major keys correctly.