For 3 x 3 matrices M and N, which of the following statement(s) is...

{\left({\text{N}}^{\text{T}} \text{MN}\right)}^{\text{T}} = {\text{N}}^{\text{T}} {\text{M}}^{\text{T}} \text{N}$is symmetric if M is symmetric and skew-symmetric if M is skew-symmetric.<br />${\left(\text{MN} - \text{NM}\right)}^{\text{T}} = {\left(\text{MN}\right)}^{\text{T}} - {\left(\text{NM}\right)}^{\text{T}}$<br />$= \text{NM} - \text{MN}$<br />$= - \left(\text{MN} - \text{NM}\right)$<br />skew symmetric<br />${\left(\text{MN}\right)}^{\text{T}} = {\text{N}}^{\text{T}} {\text{M}}^{\text{T}}$<br />$= \text{NM}$<br />$\ne \text{MN}$hence not correct<br />Standard result is<br />$\text{adj} \left(\text{MN}\right) = \left(\text{adj N}\right) \left(\text{adj M}\right)$<br />$\ne \left(\text{adj M}\right) \left(\text{adj N}\right)