What is the maximum size of data that the application layer can pass on to the…

The application layer can pass data of arbitrary length to the TCP layer. There is no strict upper bound imposed by the protocol interface at this stage. TCP handles segmentation of this data into segments, so the application is not restricted by MTU limits or 2^16 bytes when passing data. Therefore, the option 'Any size' accurately reflects the capability of the application layer in this context.