question $6$ the coefficient of variation is given by

a$.E\frac{R}{?}$ Standard devoiation

b$.$ Standard deviation $/E($R$)$

c$.$ Standard deviation per unit of return

d$.$ Both $b$ and $c$ are correct

Quesiton $7$

Amount of risk$-$reduction in a portfolio depends upon

$($a$)$Market movement,

$($b$)$ Degree of correlation,

$($c$)$ No$.$ of shares,

$($d$)$ Both $($b$)$ and $($c$).$