Solve the Problem $x$ Be the Number of Rock CDs

Multiple Choice

Solve the problem.
-A recording company is to release 60 new CDs in the categories of rock, country, jazz, and classical. If twice the number of rock CDs is to equal three times the number of country CDs and if the number of jazz CDs is to equal the number of classical CDs, how can the CDs be distributed among the four types? (Let $x$ be the number of rock CDs, $y$ the number of country CDs, $z$ the number of jazz CDs, and $w$ the number of classical CDs. Let $w$ be the parameter.)

A) $x=36-w, y=16-w, z=w, 0 \leq w \leq 20$
B) $x=30-3 w / 5, y=20-2 w / 5, z=w, 0 \leq w \leq 26$
C) $x=36-6 w / 5, y=24-4 w / 5, z=w, 0 \leq w \leq 30$
D) $x=30-2 w, y=30-2 w / 5, z=w, 0 \leq w \leq 30$