You are designing for a write-heavy application. During testing, you discover that the write workloads are performant in a regional Cloud Spanner instance but slow down by an order of magnitude in a multi-regional instance. You want to make the write workloads faster in a multi-regional instance. What should you do?

A. Place the bulk of the read and write workloads closer to the default leader region. B. Use staleness of at least 15 seconds. C. Add more read-write replicas. D. Keep the total CPU utilization under 45% in each region.