If in an election to a State Legislative Assembly the candidate who is declared elected loses his deposit, it means that

1. The question describes a scenario in a State Legislative Assembly election where the candidate declared elected also loses their election deposit. 2. Losing the security deposit happens when a candidate fails to secure a minimum percentage (one-sixth or 16.67%) of the total valid votes polled in the constituency, as per the Representation of the People Act. 3. It is highly unusual for a winning candidate to get less than one-sixth of the votes. 4. Such a situation could only arise if the votes were extremely fragmented among numerous candidates. If there is a very large number of candidates contesting the election, the votes polled could be split so widely that even the candidate with the highest number of votes (the winner) falls short of the one-sixth threshold required to save the deposit. 5. Poor polling (A) affects total votes but not necessarily the winner's share. Multi-member constituencies (B) were abolished for Assembly/Lok Sabha. Marginal victory (C) doesn't necessarily mean losing the deposit.