A piano tuner charges $63 for 1.5 hours of work. Which proportion can be used to find x, the number of dollars the piano tuner charges for 4 hours of work?

A.
x
4
=
1.5
63
B.
x
63
=
3.5
2.5
C.
x
63
=
1.5
4
D.
x
4
=
63
1.5