Contact Form 7 Drop Down Menu Instruction

Hi guys, I want to make a drop down menu like for example.

Select Payment Option
[select menu-374 “Gcash” “Metrobank” “BPI”]

Then if a user select disired option
bank account # will appear below

For example I selected
Gcash
then an instruction appear below
send your payment here Account # 123456789

[Moderator’s note: moved to How-To and Troubleshooting]