The U$-$Value $($unit$,$ i$.$e$.$: BTU$/$s$.$f$.$ F $)($mark all that apply!$)$

a$)$ measures the amount of energy transferred through a building assembly

b$)$ could be also measured in $\frac{W}{m^2}K,$ as common in other countries

c$)$ is the same as the $R-$value

d$)$ does not apply for roof assemblies