You read the following statement in a Java program that compiles and executes.

Submarine nautilus $=$ new submarine$()$;

nautilus.dive$($depth$)$;

What can you say for sure?

a$)$ depth must be an int

b$)$ dive must be a method

c$)$ dive must be the name of an instance variable

d$)$ nautilus must be the name of a class

e$)$ Submarine must be a method