Which guarantee$($s$)$ does Spanner NOT provide?

$$ Your answer: $($A$)$ If offers a multi$-$version, temporal database where data is versioned and each version is timestamped with its commit time; $($B$)$ It provides concurrency control using a lock table that keeps state for two$-$phase locking; $($C$)$ It offers external consistency via its TrueTime API; $($D$)$ It supports nonatomic schema changes.