How do pointers affect taint checking? $($Choose the one correct answer.$)$

How do pointers affect taint checking? $($Choose the one correct answer.$)$

To mitigate loss of confidential data, taint checking should encrypt all pointers, and decrypt them just before use.

To prevent use of uninitialized data, taint checking should ensure that pointers are always initialized to valid values.

To increase accuracy, taint checking should account for pointers to untrusted data.

To increase the speed of processing pointers at runtime, taint checking should ensure that all pointers are pointing to valid memory.