Which mode specifier will open a file but not let you change the file or write to it$?$

Question $12$ options:

A$)$

$\text{'}$r$\text{'}$

B$)$

$\text{'}$w$\text{'}$

C$)$

$\text{'}$e$\text{'}$

D$)$

$\text{'}$a$\text{'}$