What is the role of regression analysis in bonds?

A、Itisusedtoexplainthevalueatriskofamountsinvestedinbonds
B、Itexplainsthechangesintheyieldofonebondrelativetothechangesinyieldsofasmallnumberofotherbonds
C、Itisusedforempiricaldescriptionofthetermstructureofbonds
D、Alltheabove