The special$-$purpose couplings that can be used on turbomachines are covered by the $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.$

Question $4$Select one:

A$.$

API $671$ specification

B$.$

API $871$ specification

C$.$

API $771$ specification

D$.$

API $978$ specification

E$.$

API $999$ specification