odazvati

1. (of an invitation, call) to respond; to accept an invitation
   Mnogi građani su se odazvali pozivu za davanje krvi. — Many citizens responded to the call to donate blood.
   Nažalost, nije se odazvao našem pozivu na svadbu. — Unfortunately, he didn't accept our wedding invitation.
2. (when called) to answer; to respond when called
   Zvala sam ga tri puta, ali se nije odazvao. — I called him three times, but he didn't answer.
   Pas se odmah odazvao na svoje ime. — The dog responded to its name right away.

In both senses the verb is reflexive: odazvati se + dat. (pozivu) or na + acc.