Which of the following facts can be considered as res gestae, if A committed robbery on B?            

As per S. 7. Facts which are the occasion, cause or effect of facts in issue . –– Facts which are the occasion, cause or effect, immediate or otherwise, of relevant facts, or facts in issue, or which constitute the state of things under which they happened, or which afforded an opportunity for their occurrence or transaction, are relevant.   Illustration- (a) The question is, whether A robbed B. The facts that, shortly before the robbery, B went to a fair with money in his possession, and that he showed it, or mentioned the fact that he had it, to third persons, are relevant.