Customer B did not conduct a cash transaction for a reportable amount, nor was a reportable cash transaction conducted on behalf of Customer B,
Customer B, Customer B's CD, and the cash used to open Customer B's CD are all ignored, if the facts are as you described them.
However, if Customer A was the conductor of the purchase of Customer B's CD, the bank would include a Part I for Customer B with item 2c checked, and there would be two Part I sections for Customer A -- One with item 2a checked and one with item 2b checked, and both would have item 3 checked.
In other words, there isn't enough information in your scenario to determine the correct response.