Option 1 -> Andhra Pradesh made significant progress in rural electrification but was not the first state to achieve 100% household electrification.
Option 2 -> Telangana worked towards complete electrification after its formation in 2014 but was not the first state to reach this milestone.
Option 3 -> Kerala achieved 100% household electrification and became the first state in India to accomplish this feat under the Saubhagya scheme.
Option 4 -> Tripura achieved 100% household electrification later and became one of the early states to reach this goal, but not the first.
Hence, Option 3: Kerala -> Kerala created history by becoming the first Indian state to achieve 100% household electrification in 2018 under the Centre's Saubhagya (Pradhan Mantri Sahaj Bijli Har Ghar Yojana) scheme, ensuring electricity connections to all willing households -> correct