The Fermat’s little theorem for odd prime p and coprime number a is?

• A. aᵖ⁻¹ ≡ 1 (mod p)
• B. aᵖ⁻¹ ≡ 7 (mod p)
• C. aᵖ⁽²⁾⁻¹ ≡ 1 (mod p)
• D. none of the mentioned