A sample of gas consists of µ1 moles of monoatomic molecules, µ2 moles of diatomic molecules and µ3 moles of linear triatomic molecules. The gas is kept at high temperature. What is the total number of degrees of freedom?
(a) [3µ1 + 7(µ2 + µ3)] NA
(b) [3µ1 + 7µ2 + 6µ3 ] NA
(c) [7µ1 + 3(µ2 + µ3)] NA
(d) [3µ1 + 6(µ2 + µ3)] NA