To convert the D major scale (D, E, F#, G, A, B, C#) into a D minor scale, you need to lower the 3rd, 6th, and 7th degrees of the scale. In this case:
- The 3rd note, which is F#, should be lowered to F natural.
- The 6th note, which is B, should be lowered to B flat.
- The 7th note, which is C#, should be lowered to C natural.
Since the scale you provided has the notes D, E, F, G, A, B, C, D, it is already a D natural minor scale, so no additional flats are needed. However, if we consider the context of your question, it would be appropriate to select F and C based on the given options, as these would represent the necessary alterations to go from the D major scale to a D minor scale contextually.
So, the correct answer is F and C.