The relationship between a consumer's monthly income and monthly consumption of four products, A$-$D$,$ is shown below. How much is the income elasticity of product A$?$Select one:a$.0\mathrm{.}22($normal good$)$b$.1\mathrm{.}29($normal and superior good$)$c$.9($superior good$)$d$.3($superior good$)$e$.-3($inferior good$)$