Which property defines a 'Wieferich pseudoprime'?
A composite number nnn such that 2n−1≡1(modn2)2^{n-1} \equiv 1 \pmod{n^2}2n−1≡1(modn2)
A prime number ppp such that 2p−1≡1(modp2)2^{p-1} \equiv 1 \pmod{p^2}2p−1≡1(modp2)
A Carmichael number
A number divisible by a Wieferich prime