How are the names of functions written in MIPS assembly language programs?

How are the names of functions written in MIPS assembly language programs?

a$.$MIPS function names are addresses stored in the Control Unit

b$.$MIPS functions are character strings stored in the ALU

c$.$MIPS function names are written as labels in the text segment

d$.$MIPS function names are written as labels in the data segment

MIPS function names are pointers stored in the IR