select all true statements

Question options:

	if the returns of two risky assets have a correlation of zero, it is possible to create a portfolio with zero risk
	If you want to reduce the risk of a portfolio, you are more likely to achieve this goal with two assets with a correlation of 0.9 than with two assets with a correlation of 0.1
	If two assets have a risk of 20%, it is possible to obtain a risk of zero if a) their correlation is -1 and b) we pick specific portfolio weights
	correlation of returns is a number that ranges between 0 and 1