Which of these congruences is always satisfied by an odd prime ppp?
p2≡1(mod8)p^2 \equiv 1 \pmod 8p2≡1(mod8)
p2≡0(mod8)p^2 \equiv 0 \pmod 8p2≡0(mod8)
p2≡2(mod8)p^2 \equiv 2 \pmod 8p2≡2(mod8)
p2≡4(mod8)p^2 \equiv 4 \pmod 8p2≡4(mod8)