class Dog:

def $\_\_$init$\_\_($self$,$ name, breed, age$)$:

self.name $=$ name

self.breed $=$ breed

self.age $=$ age

Which of the following represents the correct implementation of the $\_\_$str$\_\_$ method?

a$)$ def $\_\_$str$\_\_($self$)$:

return f$"\{$self$.$name$\},\{$self$.$age$\}$ years old, $\{$self$.$breed$\}$ breed"

b$)$ def $\_\_$string$\_\_($self$)$:

return f$"\{$self$.$name$\}$ is a $\{$self$.$age$\}-$year$-$old $\{$self$.$breed$\}"$

c$)$ def str$($self$)$:

return f$"\{$self$.$name$\}(\{$self$.$breed$\})-\{$self$.$age$\}$ years"

d$)$ def print$\_$str$($self$)$:

return f$"\{$self$.$age$\}$ years old $\{$self$.$name$\}$ of $\{$self$.$breed$\}$ breed"