What kind of group ceases to exist if even one member leaves the group?

dyads

Explanation:

A dyad is a kind of group that ceases to exist if even one member of leaves the group.

Such groups consists usually of two people.

A dyad is used in sociology to refer to a group of two peopleIt can be a brother and a sisterSuch groups can be terminated when one member of the group pulls out or dies. Dyads are the simplest group structures known. Members of a dyad can be linked by education, romance, business, e.t.c

United states v.  nixon, 418  u.s.  683 (1974),  was  a landmark  united states supreme court case  that resulted in a unanimous  decision  against president richard  nixon, ordering him to deliver tape recordings  and  other subpoenaed materials to a  federal  district  court.

Complementary goods. they go together, thats why one price increase and the others demand increases