How to change "FROM" when replying to a email within the GMAIL app?

I use the default GMAIL app for my email. I have three email accounts, all linked to each other. When I receive an email sent to my personal account "PERSONAL", I want to reply from a secondary account "SECONDARY" or from my business account "BUSINESS". When I open the email and select reply, the FROM gmail account is fixed. There is no drop down shown so I can change the FROM address.

Question: How can I reply to the email with one of my other email linked accounts?

Thank you for your time

Bob

from xda-developers http://ift.tt/26IFmH3
via IFTTT