# Consider the following Python code:

def mystery$\_$function$($x$)$:

if x $>0$:

return mystery$\_$function$($x $-1)+$ x

else:

return $0$

result $=$ mystery$\_$function$(4)$

# What will be the value of 'result' after executing this code?

a$)4$

b$)6$

c$)10$

d$)15$