1.D

2.B

3.C

4.A

Explanation:

1.half note + quarter note=6 beats | dotted half note= 6 beats

2.quarter note +quarter note + quarter note + quarter note= 4 beats | eight note + half note + quarter note= 4 beats

3.double eight note+ double eight note+ double eight note= 3 beats | double sixteenth note + double sixteenth note +quarter note + quarter note =3 beats

3.quarter note+quarter note =2 beats | quarter note + double eighth note = 2 beats