Option (C) is correct because in both Rajya Sabha and Lok Sabha elections, every vote has equal value. In Lok Sabha elections (FPTP system), every citizen's vote carries equal weight within a constituency. In Rajya Sabha elections (STV system), every MLA's vote has equal value in determining the quota and transfer of preferences.

Option (A) is incorrect because the electorates are different. For Lok Sabha, every citizen above 18 is an eligible voter. However, for Rajya Sabha, the voters are MLAs of the respective State legislative assemblies, not ordinary citizens.

Option (B) is incorrect because preference voting (ranking candidates) is unique to Rajya Sabha elections using the Single Transferable Vote (STV) system. In Lok Sabha elections under FPTP, voters simply vote for one candidate without any preference ranking.

Option (D) is incorrect because the winning criteria differ. In Lok Sabha (FPTP), the candidate who wins may not get majority (50%+1) votes - they only need the highest number of votes. In Rajya Sabha, candidates must secure a minimum quota calculated by a formula, not necessarily more than half the votes.