You created a PL/SQL subprogram that successfully invokes an external C procedure. After a while, the database administrator (DBA) drops the alias library schema object. The shared library exists in the system. Which statement is true in this scenario? 

Answer options:

A. The corresponding shared library is also removed from the system
B. PL/SQL subprograms can be used to invoke the external C procedure
C. The existing extproc process is terminated and a new extproc is started
D. The PL/SQL subprogram that depends on the external C program becomes invalid

D