How many retention and sensitivity labels can be applied to an O365 item?

A、Oneretention;onesensitivity
B、Upto15retention;upto15sensitivity
C、Unlimitedretention;unlimitedsensitivityeithersensitivityorretention"
D、Onelabelonly
E、Oneauto-appliedretentionlabel;oneauto-appliedsensitivity;onemanually-effectively4intotal"appliedretention;onemanuallyappliedsensitivity