Which of the following is true regarding ϕ(p)\phi(p)ϕ(p) for prime ppp?
ϕ(p)=p\phi(p) = pϕ(p)=p
ϕ(p)=p−1\phi(p) = p-1ϕ(p)=p−1
ϕ(p)=1\phi(p) = 1ϕ(p)=1
ϕ(p)=p+1\phi(p) = p+1ϕ(p)=p+1