Idioms and Phrases - Verbal and Reasoning

In the following questions four alternatives are given for the idiom/phraseitalicised and underlinedin the sentence. Choose the alternative which best expresses the meaning of idiom/phrase.
Q1:

I am sure they will fight tooth and nail for their rights.

A with all their might

B without any other weapon

C resorting to violence

D very cowardly

ANS:A - with all their might

No answer description is available.