Provide the answer and an explanation

11. When it comes to implementing a reentrant function, which of these actions is most likely "safe" to perform (i.e., won't make the function non-reentrant)? (a) reading a global data structure (b) modifying a global variable (c) modifying a local variable (d) calling another (possibly non-reentrant) function 12. Which of the following statements concerning signal handling is false? (a) it is not possible to accurately determine how many signals of a given type were sent over a given period (b) when delivering a signal, the kernel informs the receiver of the pid of the sending process (c) signals are prioritized based on their position in the pending and blocked vectors (d) signal handlers are executed in user mode (i.e., not as the kernel)