How much data can the “Response” field support?
First, the amount of data a response field can support depends on the Operating System. iOS devices can only support up to 478 characters. However, Android and Blackberry 6/7 devices can support upwards of 13400 characters.
Note: Also, you can use the Webify option to add HTML or Web content to the Response field. Look here for more information on Webify.