Identify the line in the source code that might lead to buffer overflow?

The programmers on your team are analyzing the free, open source software being used to run
FTP services on a server in your organization. They notice that there is excessive number of
functions in the source code that might lead to buffer overflow. These C++ functions do not check
bounds. Identify the line in the source code that might lead to buffer overflow?

A.
9A.9

B.
17B.17

C.
20C.20

D.
32D.32

E.
35E.35