How are switch tables updated in a multi-switch network?

Question

I have a network structure like the below:

      Switch A - Switch D
      /      \
 Switch B    Switch C
 /  |  \     /  | \  \
1   2   3   4   5  6  7

Where 1..7 are hosts. If 1 were to send a message to 6, and then 6 responds to 1, I want to know what each switch switch table looks like.

I have an idea that B will have a switch table containing 1's host entry, C will have 4's entry, and A will have both, but what about D? My thought process is the switch tables are updated when a new frame is received, so when 1 sends a message to 6, B is updated with 1, A is updated with 1, and likewise C and A with 6.

Is D empty? I'm not sure how the tables are updated.