If gcd(a,b)=1\gcd(a, b) = 1gcd(a,b)=1 and gcd(b,c)=1\gcd(b, c) = 1gcd(b,c)=1, which statement MUST be true?
gcd(a,c)=1\gcd(a, c) = 1gcd(a,c)=1
gcd(ab,c)=1\gcd(ab, c) = 1gcd(ab,c)=1
gcd(a,bc)=1\gcd(a, bc) = 1gcd(a,bc)=1
gcd(ac,b)=1\gcd(ac, b) = 1gcd(ac,b)=1