Vector Clock Comparison and Concurrency

Three processes maintain vector clocks. Event $e_1$ at $P_1$ has vector clock $[3, 2, 1]$ . Event $e_2$ at $P_2$ has vector clock $[2, 4, 1]$ . What is the relationship between $e_1$ and $e_2$ ?

Cannot be determined without more information

$e_1$ happens-before $e_2$

$e_2$ happens-before $e_1$

$e_1$ and $e_2$ are concurrent