The primary dimensions of the gas constant over the universal gas constant $\frac{R}{R_u}$ are

$($a$)\frac{L^2}{t^2}*T$

$($b$)m*\frac{L}{N}$

$($c$)\frac{m}{t}*N*T$

$($d$)\frac{m}{L^3}$

$($e$)\frac{N}{m}$