Statement based updates to a server using row based logging
The logs will be applied in the format which they are consumed, so on Server B statement based execution is applied.

Whether or not Server B even produces binary logs depends on whether or not binary logging is enabled on Server B. https://dev.mysql.com/doc/refman/8.0/en/replication-options-binary-log.html#sysvar_log_bin
It is not required if the server is only to be a slave.

Even then, Server B will only produce binary logs related to the updates it receives from Server A if log_slave_updates is set 
https://dev.mysql.com/doc/refman/5.6/en/replication-options-slave.html#option_mysqld_log-slave-updates

The resulting log format from the slave updates depends only on what binlog_format is set as on the slave https://dev.mysql.com/doc/refman/8.0/en/server-options.html#option_mysqld_binlog-format

Keep in mind that Server A(statement format) to Server B(row/mixed format)  will work fine, but Server A(row/mixed format) to Server B (statement format) will fail. See this question for further explanation
https://dba.stackexchange.com/a/159905/129765

To answer your question tersely, Server B executes the statement based SQL and then translates it to row based SQL which it outputs to the binary logs.