If gcd(m,n)=1\gcd(m, n) = 1gcd(m,n)=1 (i.e., mmm and nnn are coprime), which statement is always true?
lcm(m,n)=1\text{lcm}(m, n) = 1lcm(m,n)=1
lcm(m,n)=mn\text{lcm}(m, n) = mnlcm(m,n)=mn
m+nm + nm+n is prime
Both mmm and nnn must be prime