which of the following statements is false?

If two stocks move together, their returns will tend to be above or below avergae at the same time, and the covariance will be positive

the closer the correlation is to $0,$ the more the returns tend tomove together as a result of common risk

Dividing the covraiance by the volatilities ensures that correlatoin is always between $-1$ and $+1.$

Volatility is the square root of vraiance.