Welcome to Ex Post Facto, the news quiz for busy legal professionals like you.

Last week 89 percent of you knew that Elon Musk is the executive who made a deal with the Securities Exchange Commission requiring that a lawyer review his tweets about company finances.

The hardest question, by far, asked which of four horses with a legal-themed name won the earliest Kentucky Derby. Only 21 percent chose the right answer Judge Himes from 1903, while 40 percent chose Affirmed from 1978.