Complex sentence: The strongest GRC team for the SDA was the one that contested Jalan Besar GRC, it was led by Sebestian Teo, with a former MP Cheo Chai Chen.
Split into simpler sentences: The strongest GRC team for the SDA was one contesting Jalan Besar GRC. It was led by Sebestian Teo and its members include former MP Cheo Chai Chen.