Synonym of CONSOLIDATE

Answer: Option C

Contrive : create or bring about (an object or a situation) by deliberate use of skill and artifice.
Connive : secretly allow (something immoral, illegal, or harmful) to occur.
Unite : come or bring together for a common purpose or action.
Conspire : make secret plans jointly to commit an unlawful or harmful act.
Consolidate : combine (a number of things) into a single more effective or coherent whole.

Synonym of Consolidate is Unite