Thanks, I now understand that Beta (asset) is a constant and remains unaffected by Beta (equity).
And regarding my second doubt, I think the author wants us to make the comparison between B’s equity beta and A’s levered Beta (which we will obtain after unlevering B’s equity beta and re-levering to suit A). I do not think his intention was to ask us to compare A’s asset beta to A’s equity beta (if so, then the latter would be more than the former, even if A had a debt-equity leverage between 0 and 1). Correct me if I’m wrong?