Pairing Data 2-D array

I have class A.
I have a class B with attributes c and d.
A has many Bs.

I get an instance of A using
a = find_by....

I can get a listing (enumeration) of values for attribute b using map
function.

   a.b.map{ |x| x.c}

c1
c2
c3

However, I want c and d returned and paired together in an array like a
2-d array.

c1 d1
c2 d2
c3 c3

What's the best way to do this? Map won't work, correct?

You can do an array of arrays:

a.b.map {|x| [x.c, x.d]}