A. Debug logs can be set for specific users, classes, and triggers:

Debug logs can be configured for users, classes, and triggers by setting trace flags.

C. Only the 20 most recent debug logs for a user are kept:

Salesforce retains only the 20 most recent debug logs per user. Older logs are overwritten.

E. The maximum size of a debug log is 5 MB:

Debug logs are capped at 5 MB. If this limit is exceeded, logging stops for that transaction.

Why Not B and D?

B: Debug logs are retained for7 days, not 24 hours.

D: Debug log levels are not cumulative. Each level is independent.