Key of D major notes E G A C#. Which names describe the chord? EMaj7, Dom 7 in D, E7, DMaj7, A7, Dom 7th on A

Question

Key of D major notes E G A C#. Which names describe the chord? EMaj7, Dom 7 in D, E7, DMaj7, A7, Dom 7th on A Choose more than 1. I identified A7

Answer 1

Philip, we know its not EMaj7, E7, DMaj7.

 

We know that it is A7. Since it is rooted on A, it’s also Dom7 on A. Since it is V⁷ for D, it makes sense that it is Dom7 in D.