Did you follow any of that?
The Indonesian-English pair doesn’t match.
Apa kamu mengikuti perkembangannya? = Did you follow the development?
Apa kamu mengikuti salah satunya? = Did you follow any of that?
By the way, the Indonesian author frequently uses “kau” for “you”, but it’s a dialect. The vast majority regard “kau” as an impolite word and they avoid it. I heard that people on Sumatra Island use “kau” as a shorten form of “kamu” without such a negative connotation.