I am putting together a pricing tool.

For example, in A1 - I have a drop-down list with CVR, Metro CVR and
InterCity CVR

Each name in the list is associated with a set of cities where the
service is available with specific service rates,

CVR - ATL, MIA
Metro CVR - DC, NYC, SEA
InterCity CVR - CHI, STL, NAS

So if I pick CVR in the drop down list in A1, the drop down list in B1
should only show ATL and MIA.

HELP!