What command prints available functions?

What command prints available functions?

A.
declare -f

B.
set

C.
typeset

D.
function()

Explanation/Reference:
From the man pages:
declare [-aAfFilrtux] [-p] [name[=value] …]    Declare variables and/or give them attributes. If no names are given then display the values of variables. 

The -f option will restrict the display to shell functions.