Deutsch, the subject of the sentence, is a masculine noun. The verb «ist» is the third person singular form of «sein» (to be) in the present tense. The adjective «wichtig» means «important» and is used here in its base form because it follows the verb «ist» and does not precede a noun. The phrase «dass der Antwort auf Russisch ist» is a subordinate clause introduced by «dass» (that). In this clause, «der Antwort» is the subject, and «auf Russisch» is a prepositional phrase indicating the language. The verb «ist» is again the third person singular of «sein» and is placed at the end of the subordinate clause, which is standard in German sentence structure. The entire sentence translates to: «It is very important that the answer is in Russian.» This structure emphasizes the importance of the response being in Russian, which is a key requirement in the given context.