Which can be true for diversified portfolios with more than one asset?

A$)$The correlation coefficient between the returns on two assets will always have a value between $0$ and

$+1.$

B$)$If the correlation is negative: returns tend to have opposite signs.

C$)$If the correlation is positive: the return on one asset is positive and the return on the other asset

tends to be negative.

D$)$For a correlation of $+1,$ the returns on the assets are not correlated.