Final answer:
Type 4 JDBC drivers, known as thin drivers, are true Java drivers that can be used on any platform supporting DBMS protocol because they are written entirely in Java.
Step-by-step explanation:
The statement about Type 4 JDBC drivers that is true is: A. Fully written in java, can be ported to any platform that supports DBMS protocol. Type 4 drivers, also known as thin drivers, are pure Java drivers that convert JDBC calls directly into the vendor-specific database protocol. This allows them to be platform-independent, as Java is a platform-agnostic language. Hence, they can be used across any platform that has support for the database management system protocol. This feature also aides in making the driver portable across different platforms without the need or concern of client-side libraries.