The values of the remainder $r$,when a positive integer $a$ is divided by $3$ are $0$ and $1$ only. Justify your answer.

(B) No.
According to Euclid's division lemma,for any positive integer $a$ and a divisor $b=3$,there exist unique integers $q$ and $r$ such that:
$a = 3q + r$,where $0 \leq r < 3$.
Since $r$ must be an integer satisfying the condition $0 \leq r < 3$,the possible values for the remainder $r$ are $0, 1,$ and $2$.
Therefore,the statement that the remainders are only $0$ and $1$ is incorrect.